My friend, former co-worker, and industry legend Tom Hall (creator of Commander Keen, Anachronox, co-creator of Wolfenstein, Doom, Anachronox and others) has launched a Kickstarter for a new game that is both a spiritual successor to Commander Keen, as well as a super nifty game-building app (think Minecraft, or Little Big Planet). Check it out and if you have the spare coin, please back it!
http://www.kickstarter.com/projects/368238381/wo rlds-of-wander-plus-secret-spaceship-club-game
Cyberdevil
If it was a successor to Doom I'd happily fund it, Commander Keen was a bit before my time though, but it looks good.