Can be bought online at 3D Realms.
Lots of resources for the Keen series can be found on Beyond the Pogo.
Buy on Digital Stores
Commander Keen 1: Marooned on Mars is available for a small price on the following websites, and is no longer abandonware.
English 
Comments and reviews
Would enjoy a Shareware link for any game listing that needs a purchase
Press and hold the G, O, and D keys during game play...
I can play and i use F2 to enable the sound but i hear nothing and just walk around in the 4th screen shot http://www.myabandonware.com/media/screenshots/c/commander-keen-1-marooned-on-mars-uv/commander-keen-1-marooned-on-mars_4.gif how do i get passed the space rock blocking the trail?
I love commander keen
Fought w my sisters to play
I guess there is a lot of people that have no clue what SHAREWARE is or was. As the name implies you SHARE it with whoever you like and the game has its own marketing page in it with how and were to buy the rest of the game because like software nowadays they gave you some levels for free but to play the rest you needed to pay. This game might not be ABANDONWARE but the publisher might not have said anything because in here they are doing them a favor by giving it away for newer gamer to try and hopefully buy it.
ich heyse
Great...from my some yonger days onwards....now Im close to 50 !! Still Im playing (hey...dont laugh at me. Truely I play it, even I hope when in the other world to bring a copy of Keen with me...
Great website
my older brother loved this game, and i love it too!
thanks this is a great game!
@Videogamer555 Commander Keen 1 is actually Shareware, The first commander keen was given out to whoever wanted to download it, You can actually download it w/out paying on 3D Realm's site. The rest of them, they make you pay for though.
Unfortunately ID Software (the maker of Commander Keen 1) is in fact selling the game still at their website. It is not abandonware.
http://www.idsoftware.com/games/vintage/ck-vorticons
I'm not a representative of the company, but as a good citizen, I feel it is only right of me that I ask you to remove this software, as it is piracy to offer downloads for software which is still for sale.
You're right @Videogamer555... We offer this game but if id software asks us to remove it, we will delete it immediately !
Ahh Cmdr Keen, easily one of the best Shareware games ever made.
Tt's 20% better than Mario, it's just FABULOUS!
ya so cool
Awesome!
Thanks!
This is a mario for dos!
For a retro, PC game... this is the best game in the world.
I've played it since I was younger than 6 years old and still love it!
I don't think I will ever get sick of this game.
@Commander Dude: Same here. Classic!
Goal : Take all part that you can to complete!!
And you're in Mars... Or you're in another planet.
I love these games! These were the first games I ever played on a PC!
No comment nor review for this game at the moment.