Commander Keen 1: Marooned on Mars

aka: Commander Keen: "Invasion of the Vorticons" - Episode One: Marooned on Mars
Moby ID: 216

Description official description

Billy "Commander Keen" Blaze, an eight-year-old genius, has flied to Mars in his Bean-with-Bacon Megarocket build out of common household objects. But while Keen was exploring Mars, the alien Vorticons stole vital parts from his ship and hid them in the Martian cities. Now Keen must find the stolen parts if he wants to return to Earth.

Commander Keen 1: Marooned on Mars is the first in a series of platform games. Your objective is to find the 4 missing parts to your ship.

The game begins with a top-down map of Mars. This is the level select screen, where you can walk around and choose the next level you want to enter. On each level, you have to find the exit, and possibly grab a missing rocket part which may be on the level. Once you reach the exit, you're back on the map of Mars.

The levels are typically full of enemy creatures. Most numerous are Yorps, which are mostly harmless, if annoying, but other creatures are a genuine danger. If Keen gets shot or touched, or falls into a pit or some hazardous object, he dies, and you're booted out of the level back to the map of Mars and lose one of the lives.

Thankfully, Keen can defeat some of the enemies with his raygun. He can also find a pogo stick which allows him to jump very high. Other items to find include keycards that open locked doors and bonus items which give score (Keen gets an extra life if he collects enough score).

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Credits (DOS version)

4 People

Creative Director
Graphics / Artwork
Level Design



Average score: 80% (based on 4 ratings)


Average score: 3.5 out of 5 (based on 80 ratings with 8 reviews)

The first game in a great series

The Good
Before they came out with the popular first-person shooter, Wolfenstein 3D, id Software made a trilogy of platform games that centers on eight-year-old Billy Blaze, an ordinary school kid who creates an interstellar spaceship, which he calls his “Bean-with-Bacon Megarocket”, using objects he finds around his house. He dons his brother’s helmet, and transforms into Commander Keen. The first episode, entitled ‘Marooned on Mars’, has Keen exploring the red planet to recover four vital components to his ship that the inhabitants stole while he is out exploring.

Therefore, the object of this Commander Keen episode is to recover all four parts scattered around Mars. When you begin the game, you are presented with a top-down view of the planet, in which you walk along a pre-defined path until you come across a building. Entering it gives you a side view where you need to get your hands on a raygun and get to the exit. Some areas of the building are locked behind colored doors, meaning you also need to collect keycards corresponding to that color.

There are two common lifeforms on the planet, and the first type you will encounter are the Yorps, friendly, one-eyed aliens that Keen eventually takes a liking to. They have the habit of getting in your way (especially in narrow gaps), even pushing you off the platform you are on. One way of dealing with them is by jumping on their heads to immobilize them for a few seconds. They make this cute sound as they go down. Then, you have the Gargs, who are much bigger than the Yorps. They walk around flashing their teeth. Like Yorps, they stop to survey their surroundings, and they charge at Keen when they spot him. Contact with a Garg results in a loss of life and a kick to the overhead view.

Once you have left that one building, a blue square with the word “Done” in huge letters take its place, and you can proceed on. Occasionally, there are shrines that you can enter. In these levels, you make your way to the top, avoiding hazards and enemies, and touching a Yorp statue which gives Keen a telepathic message. One of these hints is about the Standard Galactic Alphabet, the strange symbols you see throughout the game. An earlier shrine lets you retrieve a pogo stick, enabling Keen to get to places he is unable to reach by foot. The pogo is carried over to the rest of the series.

Also scattered around the buildings are various items that add to your score. The most common of these are lollypops, but you can also collect soda cans, pizza slices, textbooks, and teddy bears. Get enough of them, and you might earn an extra life. But if you happen to lose a life, you have to collect them again.

There is no background music while you are playing the game, but the sound effects are nice. You hear Keen's footsteps exactly as you should (both on the map and the normal levels.) The pistol sounds like a cartoon laser gun, and when Keen uses his pogo stick, it makes a nice boing. The sound of Keen dying is good, too. I love the way that Keen looks when he is hit, losing his whole torso, his legs still walking, and his mouth formed into an O-shape.

The controls are easy to use. Only one key can be pressed to make Keen jump, another to activate his pogo stick, and another to bring up the status panel which reveals your score, the number of lives, keycards that you have collected, and more. Before the game, I enjoyed reading the in-game story and watching the static previews of the next two episodes.

The Bad
When you are playing the normal levels, there is always that bland gray background that does not go well with me at all. It can get boring at times.

As I said earlier, you have to press a key to bring up the status panel which shows a lot of information. It would have been nice if that information would be displayed while you are playing the game, and to not have to press a key at all.

In order to fire your pistol, you have to press two keys: [Ctrl] and [Alt] at the same time. Since you are jumping or using your pogo stick most of the time, you may accidentally fire your pistol.

All these problems are rectified in the future Keen games.

The Bottom Line
Commander Keen is episode one of a great series. It may have the simple plot of retrieving stuff for your gizmo, but it is better than the games that involve you rescuing a damsel-in-distress. This game is ancient, but id did not throw in some timer problems, and that means that you will not have a problem running the game on modern systems. If you like platform games, especially the ones that involve you walking around a map and traveling to your next destination, then you won't go wrong with this one.

DOS · by Katakis | カタキス (43051) · 2021

Who said side-scrolling platform games were not possible on PC's?!

The Good
Cute and colorful graphics. The gameplay was also great for it's time. Smooth scrolling gameplay was never (or at least not that I now of) seen before in platform games on the PC. Some cool innovations such as a pogo stick to jump higher made this game an instant classing. The gameplay was similar to that of Super Mario Bros. at some points, but it was not just another attempt to clone that game. The story was different from the classic "save the princess" formula. You are eight year old genius Billy Blaze and must stop the Vorticans from destroying earth. Billy travels to Mars in this first episode in a trilogy (this game was one of the first that were distributed following the infamous "get part one free as shareware and get the sequels too by buying them" idea that was used in a lot of Apogee games and many publishers have copied). On Mars his ship gets sabotaged by the Vorticans and now you need to collect the stolen parts to repair the ship and help keen continue his adventures. This story was quite original at that age.

The Bad
Some things are a bit dated now such as finding keys to put in the corresponding doors and the gameplay doesn't also quite do the job anymore after 15 years. When this game was released it didn't really have notable flaws, however.

The Bottom Line
Though this game is a bit too dated at certain points it's still a brilliant game that is still free available as shareware and you can still buy it's sequels. If you are looking for a good classic platformer on the PC, you may want to pick this one up.

DOS · by Rensch (203) · 2005

One of the first scrolling platform games for our beloved PC

The Good
First of all, it was (and still is) absolutely free ! Because the game was shareware, this first episode was kindly given to you, in hope that you would buy episode 2 and 3 (you still can!).
Second, if my memory serves me weel, it was one of the first scrolling platform games on the PC.
The gameplay was correct, with several nice features not so commonly seen : the pogo, allowing you to make giant jumps, but which can be controlled in a more difficult way (this is intended, not a control bug !). And also, some ennemies would just push you, sometimes into deadly traps, instead of killing you on contact.
Graphics were more than decent, with funny ennemies and some pieces of nice animation.

The Bad
While most of the graphics were decent, there is no real background to speak of, but this was addressed in the following episodes.
While the gameplay was generally good, it also introduces the "find the yellow key to open the yellow door" trick that would faithfully appear in just about every apogee platform game. While this is not really a commander keen's problem, this is the start of a habit that gets nasty after ten games.
The lastability of the game is abysmal as it can be completed in 2 hours. This, though, is a problem you can easily forgive, as this first episode is kind of a free teaser for the following games in the serie. However, I have no idea if further episodes suffer from the same shortness.

The Bottom Line
Commander Keen is certainly a game to be admired : it was one of the first (and still rare) successful shareware game. It also was a technical achievement, with its scrolling platform action. But, as far as pure gameplay pleasure is concerned, Commander Keen is slightly more than average. A game to be respected for sure. Knowing wether it has to be worshipped is open to debate.

DOS · by Xa4 (300) · 2003

[ View all 8 player reviews ]



Tom Hall (via Classic Gaming):

The first game was actually a joke. It was called Dangerous Dave in 'Copyright Infringement.' (John) Carmack had just gotten a little guy to move around over a tile map, and I looked over at the Nintendo in the corner. I said, 'Wouldn't it be funny to make the first level of Super Mario 3...tonight?' Carmack smiled and said, 'Let's do it!' I copied the tiles pixel for pixel and made a map out of them while Carmack feverishly programmed the guy landing on ground tiles and getting coin tiles. At 5:30 in the morning, we dumped that on (John) Romero's desk and went home to crash. Romero played it all the next day, saying 'This could make so much money!' It was pitched to a friend of a friend at Nintendo, and they liked it so much, they wanted a demo. We added Mario graphics and Koopas and stuff, and sent it to them. It apparently got to the head guys at Nintendo, but they didn't want to enter the PC market.

Softdisk didn't want to use the smooth scrolling trick Carmack had discovered (since it didn't also work in CGA!), so we thought, well, if they don't want it, we could do something ourselves.... So we thought, hey, we'll make our own game. We needed a topic. I asked if they cared what topic-sci-fi, fantasy, whatever. I think Carmack mentioned a kid that saves the galaxy or something. I went off and fifteen minutes later, came back with the paragraph that you see in Keen 1. I read it in a Walter Winchell voice (he's a nasal 40s radio/newsreel announcer). Carmack clapped after I was finished, and we were off and running.

We got contacted by Scott Miller of Apogee, and once Keen was published, it was making enough for us to live on, so we quit and formed id.


There are some level packs and even mods (files changing the graphics in the games) circulating for this game.


Throughout the game there are references to Keen's grandfather, whose name is William J. Blazkowicz. Interestingly, William J. Blazkowicz is the main character in Wolfenstein 3D, id's first person shooter made two years later.


The writings on the signs in the game actually make sense. Much like the runic writing in Ultima, you can translate it letter by letter and discover what they mean. There is a table to help you translate all those messages on 3drealm's website.


Marooned on Mars is the first of three episodes of the series Commander Keen: Invasion of the Vorticons.

Information also contributed by Accetone, Maw and Xa4

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Contributors to this Entry

Game added by Tomer Gabel.

Additional contributors: Xa4, Frenkel, Pseudo_Intellectual, formercontrib, Patrick Bregger.

Game added August 14th, 1999. Last modified August 29th, 2023.