Commander Keen in Invasion of the Vorticons – Episode One: Marooned on Mars

In 1981, a company named Softdisk was founded in Shreveport, Louisiana. Some time later, they hired an alumnus from the University of Missouri named John Carmack. Despite not leaving the college with a degree, Mr. Carmack was an exceptional programmer – particularly in the field of the rising new medium of video games. He was initially hired to work on Softdisk G-S, an Apple IIGS publication. There, he met another programmer by the name of John Romero. With the help of Michael Abrash’s Power Graphics Programming, Mr. Carmack developed an engine capable rendering graphics capable of smoothly scrolling in any direction. This was practically unheard of at the time; IBM computers available for commercial use were not able to replicate such a feat.

With an engine capable of scrolling graphics to hand, it was only natural for Mr. Carmack and his colleagues to use it to create a game. Coworker Tom Hall encouraged Mr. Carmack to demonstrate the engine by recreating the first stage of Nintendo’s landmark platformer, Super Mario Bros. 3, which had been released internationally in 1990. Mr. Carmack and Mr. Hall were then able to do just that in a single night using a character the former had created for a previous game he called Dangerous Dave. The game, cheekily titled Dangerous Dave in Copyright Infringement, was then shown to Mr. Romero, who realized the implications of being able to bring the success Nintendo had enjoyed to personal computers.

PC gaming survived the 1983 North American crash by virtue of being a niche market and therefore largely unaffected by whatever problems had plagued the mainstream. The team’s manager, Jay Wilbur, was impressed with their work and recommended that they contact Nintendo themselves in the hopes of being able to create an authorized port of Super Mario Bros. 3 for PC platforms. This team of programmers, now going by the name Ideas from the Deep, spent the next three days working on the demo for the hypothetical port. Although Nintendo praised the efforts of this budding team, they ultimately turned down the offer, wishing the Mario series to remain exclusive to their own consoles.

Undeterred, the Ideas from the Deep team convened to come up with a completely original idea. Mr. Hall suggested giving the game a science-fiction theme, which prompted Mr. Carmack to envision a child prodigy saving the world. The protagonist’s name would be Commander Keen. It was after Mr. Carmack read the premise in an overdramatic voice that the group knew they had a winning idea on their hands.

The first three games in this new series, Marooned on Mars, The Earth Explodes, and Keen Must Die!, formed a trilogy called Commander Keen in Invasion of the Vorticons. They were all released simultaneously in December of 1990. The Ideas from the Deep team distributed their game using the shareware model pioneered by their publisher, the Garland, Texas-based Apogee Software. Specifically, the episodes could be obtained individually for fifteen dollars apiece or in a single lump sum for all three at the cost of thirty dollars – all via mail orders. This way, buyers could choose between paying an amount smaller than the price of a full game for one episode or a comparatively cheaper sum for all three. This distribution method proved to be a success for Apogee, as their sales levels had jumped from $7,000 per month to $30,000 by Christmas of 1990. Speaking retrospectively, it was speculated that this trilogy of games moved at least 50,000 copies. As a trilogy of games that afforded PC users an experience many of them otherwise had no access to, could they be said to possess the same timelessness of their primary influence?

Analyzing the Experience

Billy Blaze is an eight-year-old genius who has just created an interstellar starship using old soup cans, rubber cement, and plastic tubing. With his parents in town and his babysitter asleep, he dons his brother’s football helmet, thus becoming Commander Keen: Defender of Earth!

Keen uses his starship – the Bean-with-Bacon Megarocket – to travel to Mars. Unfortunately for him, aliens from the planet Vorticon VI are well aware of his presence and plan his downfall. While exploring the surface of Mars, the Vorticons steal vital parts of his starship, hiding them in the various settlements there. With Keen now marooned on Mars, he must recover all of the ship’s parts so he may return to Earth – hopefully before his parents get home!

Mr. Carmack’s project ended up significantly different from the port of Super Mario Bros. 3 he and his team intended to develop, but one striking similarity between the two games lies in how they begin. Once you opt to begin a new game, rather than starting on the first stage immediately, you are taken to a world map. Unlike the world map in Super Mario Bros. 3, this one functions a little bit more like that of a contemporary Japanese role-playing game in how Keen isn’t locked onto a grid, and you can move him to any traversable spot. Despite this, the basic idea of the world map is the same. The blue icon represents a Martian settlement. This is the first stage in the game, and its position on the world map ensures Keen cannot simply walk past it. In order to begin the stage, all you need to do is guide Keen to the settlement and press the “CTRL” key.

Having used Super Mario Bros. 3 as a base, Marooned on Mars is a two-dimensional side-scrolling game with a heavy emphasis on platforming. By default, you use the left and right arrow keys to move Keen. Jumping is accomplished by pressing the “CTRL” key. The exact height Keen will jump depends on how long the “CTRL” key is held.

Littered throughout the first stage are green aliens called Yorps. They are harmless, although they push Keen slightly when they run into him, which can result in him tumbling into a spike pit or other hazard if the player isn’t careful. They can be stunned temporarily by jumping on them. Although this harks back to the gameplay found in the average Mario title, it’s important to know that you should not resort to such a tactic when dealing with other, more hostile forms of Martian life. In terms of survivability, Keen is less like Mario and more like Bill Rizer or Lance Bean from Contra, for he too is killed in one strike from any attack. There is no way for him to take an extra hit, as there are no power-ups to speak of.

Instead, Keen’s primary means of defense is a Raygun, which can be fired by pressing the “CTRL” and “ALT” keys simultaneously. The bolt travels forward and damages whatever organic foe it hits. Most enemies are killed in a single shot, although the Vorticon guards who watch over the stolen ship parts require four to vanquish.

During his travels, Keen will gain one significant upgrade in the form of a pogo stick. Once collected, the pogo stick can be used by pressing the “ALT” key. The pogo stick allows Keen to jump significantly higher than he could otherwise, although it’s not as useful when making leaps across expanses. This is because Keen will continue to bounce until the pogo stick is put away, which is also accomplished by pressing the “ALT” key. The pogo stick is an interesting upgrade that provides tangible benefits while also subtly discouraging players from abusing it.

Although Mr. Carmack and his team clearly took a lot of inspiration from Super Mario Bros 3., playing through the levels reveals that they took a very different approach in terms of level design. In the average Mario game, your only real goal was to reach the end of the stage. By Super Mario Bros. 3, there were various paths you could take to reach your destination, but, with the odd exception occasionally thrown in, the general idea of how to reach your destination remained the same: go right.

While following this mantra will guide you to success in the game’s first stage, later ones prove to be a little more demanding than that. Indeed, the stage design present in Commander Keen’s inaugural game is significantly more mazelike than that of your typical 1980s platformer. It doesn’t offer the same degree of exploration one would find in titles such as Metroid or Wonder Boy III: The Dragon’s Trap, but there are safeguards in place to prevent you from simply waltzing into the exit of most stages from the onset.

Said safeguards take the form of locked doors. Doors come in four different colors and must be opened with the matching keycards. Once you have the appropriate keycard, it is used automatically upon touching the door. If you forget which cards you have obtained, you can press the “ENTER” key to view the inventory screen.

If it’s one good thing you can say about Marooned on Mars, it’s that it managed to be an impressive technical achievement in 1990. Mr. Carmack was among the first to successfully take the most significant advantage afforded to the third generation of consoles – the ability to scroll smoothly – and transplant it into a DOS program.

I also give him and his team a lot of credit for successfully carving an identity distinct from that of their primary inspiration. Even just observing certain tiles in this game betrays the cues they took from Super Mario Bros. 3, but the level design was borne from distinctly Western sensibilities. While Eastern platformers typically set players on a linear path, Mr. Carmack and his team allows players a degree of exploration one would expect out of a Western adventure game. By taking a genre that was largely codified in the East and imbuing it Western sensibilities, they created something wholly unique at the time.

Unfortunately, what they did end up creating also falls woefully short of the admittedly high standard Super Mario Bros. 3 set for them. Platformers live and die based off of how effortlessly you can maneuver your character, and it is crystal clear when playing Marooned on Mars back-to-back with Super Mario Bros. 3 which game has the superior controls. The controls in Marooned on Mars can only be described as clunky. Because there is no run key, Keen doesn’t really have any sense of momentum. It doesn’t take long before he begins moving at maximum speed, and he more or less comes to a dead stop as soon as you release the key.

I will say that this by itself isn’t a major problem. Mega Man 2, one of the best platformers on the NES, functioned largely in the same way. However, the main difference is that Mega Man was designed around the heavy amounts of combat players had to perform for the boss fights. It therefore made sense for that game to lack a run button. Conversely, Mario never had an especially heavy emphasis on combat, opting to offer more complex platforming challenges instead. The reason it ultimately does bear mentioning is because Marooned on Mars fails to commit to either of these design templates. It features many Mario-style platforming sections, but with the slower-paced, combat-friendly rubric Mega Man pioneered. The result is a game that really doesn’t do anything well, offering very simple platforming challenges and with fairly weak enemies standing in Keen’s way.

What I find to be especially damning about the controls is just how unresponsive they are. Everything you do has a short, yet noticeable delay to them. This is especially noticeable when jumping. Unlike Mario or Mega Man, Keen is actually seen bending his knees to jump, and this animation takes a just a little under a second to fully render. This simply does not work in a platforming game – especially one in which your character is incapable of taking a hit without dying. Now, to be fair, the enemies in Marooned on Mars are not especially threatening. Even the titular Vorticons, which require four shots to kill, are fairly slow and easy to predict. Regardless, that slight delay can be the difference between evading an enemy onslaught and dying.

Then again, even the simple act of attempting to fire the Raygun is rendered unnecessarily difficult. The default controls require players to press the “CTRL” and “ALT” keys to fire a single shot. Why this action couldn’t have its own key is unknown. You can map the controls to your liking, but it will not solve this problem because there are only two action keys available to bind. This means that, regardless of any custom layout you may choose, you will always need to press two keys to fire the Raygun. This can easily result in you wasting ammunition whenever you’re attempting to jump or use the pogo. While it bears repeating that the enemies aren’t especially tough, ammunition is rather scarce, so you don’t want to waste charges if you can help it. You also do not ever want to be in a situation where you are out of ammunition because even the weaker enemies can easily finish Keen off if he has no means of defense.

Despite everything the game has going against it, I would have to say its fatal weakness is that it doesn’t properly incentivize players to engage with it. There are sixteen levels on Mars, but only six are strictly required to complete the game. Two levels cannot be passed until you have completed them, and the remaining four house the ship parts. One of the optional stages is home to the pogo, which you need to complete the game. The pogo can also be obtained in what is intended to be the final stage, although it’s easier to go through the optional area to get it. However, even if one were to count that as a mandatory stage, it still means slightly more than half the game can be skipped outright.

There is no incentive to complete any of the other optional stages other than the fact that some of them provide hints. Naturally, once you are privy to the information provided by the hints, the incentive to visit the respective stages vanishes completely. Theoretically, one could go through the optional stages in an attempt to achieve a high score, but this proposition too falls flat. Setting aside the inherent lack of value of achieving a high score in a non-communal setting, there is a way to achieve infinite points. One stage in the game can be completed by reaching a hidden exit. If you use this hidden exit, the stage isn’t considered cleared, so with enough patience, you can go through it multiple times until you have all the points, extra lives, and ammunition you could ask for.

Again, I will say that this isn’t an unworkable idea. Many of the stages in Super Mario Bros. 3 are not blocking mandatory routes. In fact, thanks to a certain secret item, it’s entirely possible to reach the final world without fighting a single boss. However, Super Mario Bros. 3 is such a fun game that certain players wouldn’t feel a sense of completion unless they completed every single level. Even ignoring that, certain circumstances in Super Mario Bros. 3 have a chance of rendering previously optional stages mandatory – something Marooned on Mars never does. Indeed, with players wrestling the subpar controls in Marooned on Mars every step of the way, they wouldn’t want to risk losing lives unnecessarily. If they knew which levels are mandatory, they would likely make a beeline for them to avoid having to fight that uphill battle any longer than necessary.

Drawing a Conclusion


  • It managed to be a remarkable technical achievement for its time, but doesn’t have much to offer now


  • Boring level design
  • Slippery controls
  • Fragile protagonist
  • Extremely short
  • Not especially challenging
  • Annoying sound effects
  • No music
  • Little incentive to complete all stages

In the grand scheme of things, it can be difficult to appreciate just what a remarkable technical accomplishment Marooned on Mars managed to be. The idea of having the screen of a game scroll when your character reaches the edge of the visible playing field is one that everyone takes for granted nowadays. It’s difficult to imagine the medium ever existing without that feature, yet up until the release of Marooned on Mars, it was an utterly foreign concept to PC gaming. Up until 1990, games released on any kind of personal computer required players to guide their character to the very edge of the screen before a transition occurred. While titles such as King’s Quest and Metal Gear were designed with this limitation in mind, it especially stood out whenever a game originally released for a home console was ported to a PC platform – a striking example being the MSX port of Castlevania. Therefore, the success of Marooned on Mars as a piece of shareware was an instrumental first step in allowing PC gaming to make up the ground they had lost to the console market following the smash success of the Nintendo Entertainment System.

Unfortunately, as much of a step forward for PC gaming as Marooned on Mars was, none of that goodwill translates to a worthwhile experience today. In a lot of ways, Marooned on Mars is to PC gaming what Super Mario Land was to the Game Boy. Super Mario Land was arguably inferior to Super Mario Bros., the game from which it took inspiration, yet it offered an advantage its distant predecessor did not. Specifically, it was portable in an age when the idea of playing games outside of one’s house or the arcades was practically unheard of. This situation ensured that the games did not have to directly compete with each other.

In a similar vein, Marooned on Mars was a game that got by and earned a following less on the merits of its quality and more by virtue of providing a certain subset of enthusiasts an experience they otherwise would not have had. Platformers were a nigh-nonexistent breed on the PC market, and 1990 was a time in which very few households possessed multiple game platforms. This meant having to stick with whatever you could get on the one platform you did own. So, while NES owners had no shortage of good platformers to choose from, the most common alternative to Marooned on Mars for those who only had their trusty PC to fall back on was nothing. The second-most common alternative, when considering the presence of the DOS port of Mega Man released in the same year, was less than nothing.

The one key difference between the two games, however, is that Super Mario Land is still perfectly playable by today’s standards. It may not have aged well, but anyone familiar with platformers can adjust to its bizarre physics engine and might even go as far as appreciating its novel ideas. If it fell short of the standard Super Mario Bros. set, it’s primarily because technical limitations necessitated the development team to compromise its quality. The same cannot be said of Marooned on Mars. Between its bland design, short length, and bad controls, there is little chance anyone approaching Marooned on Mars with a modern perspective will have fun with it. In the end, Marooned on Mars brought a lot of technical innovations to PC gaming, and while its position in the medium’s history is a secure one, experiencing it for yourself is not worth the effort.

Final Score: 3/10

7 thoughts on “Commander Keen in Invasion of the Vorticons – Episode One: Marooned on Mars

  1. A fascinating review you here. I can’t say I ever heard of this but it does look like some of the map designs are similar to what was accomplished in Pokemon, which is my biggest source of reference to games like these. Thanks for sharing though. How do you even pick the games you plan on reviewing on your blog? 😮

    Liked by 1 person

    • I’m not too surprised. I feel it’s one of those instances where you kind of had to be there to really get this game because while it is an important part of PC gaming history, it was ultimately overshadowed by id Software’s later accomplishments (most notably Doom). Implementing an engine capable of scrolling graphics was a major boon to the PC platform, but platformers didn’t really take off on PCs afterwards because platformers didn’t really complement the common PC interface at the time, being better suited for first-person shooters, adventure games, real-time strategy games, and the like. It wouldn’t really be until PCs more easily allowed console controllers that genres like platformers would begin appearing regularly on PCs.

      Liked by 1 person

  2. I remember playing PC platformers at friends houses. I don’t remember the specific games, except for Prince of Persia, but I do remember that not a one that I played gave a better platforming experience than even the mediocre games on console. Of which there was a lot. Platformers was like the default genre back then. The PC just wasn’t well suited for it, back then. Of course, by that point, games like Doom and Duke Nukem 3d and others did really show what PC gaming was capable of, and I always wanted to go for those, not having one of my own, but nope. My friends had strange tastes.

    That said, Commander Keen here sounds like a spectacularly bad example of the genre. Why in the world would you set it so you’d need two buttons to fire? You’ve got a keyboard you’re working with! You’ve got way more than two buttons to use! Even with everything else, that alone seems an example of just what mess the controls are.

    Liked by 1 person

    • Now that you mention it, I remember playing one of the original Duke Nukem games at a friend’s house on their computer. I remember thinking it odd how similar it ended up being to Commander Keen. It was always interesting seeing what games were installed on other computers back then. But no, in perfect 20/20 hindsight, you’re right; even NES’s mediocre platformers such as Mega Man 6 were usually better than what was offered on PCs in the early 1990s. It’s as you say; the PC just wasn’t suited for the genre. Ostensibly, a joystick could alleviate these problems, but not really. My brother installed Wolfenstein 3D on one of our old computers, and I had a blast with it.

      Commander Keen wasn’t really a bad game in a vacuum, but even in 1990, it was way behind what Nintendo accomplished with Super Mario Bros. and its sequels. And no, there is no excuse for requiring two buttons to fire the weapon, and I think Mr. Carmack and company realized that very quickly because the next set of games would have a separate button for firing. But even on the NES, requiring players to press two buttons to fire would be completely inexcusable.

      Liked by 1 person

  3. Pingback: Listening/reading log #20 (May 2021) | Everything is bad for you

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