hyperagathon: Just in case someone takes a look at these and goes "I'm not going to check each of those out", here's a few recommendations, (hopefully) not including very well-known games:
+ 3089 - Procedurally generated FPS/RPG. This guy had made a career out of these. But checking the Desura page, it's no longer supported there. Sad.
+ 8-bit Commando - (S)NES-like action platformer.
+ Great Permutator - Puzzle game for people who want their puzzles to be solvable through logic.
+ Inescapable - This already got a shout out, but it bears repeating, it's really a metroidvania gem.
+ Soul Caster 1&2 - Sort of like Gauntlet (or Hammerwatch if you don't know Gauntlet) with tower defense. Or trap defense. Entrapment? Made by the guy who did Escape Goat, which is on GOG, so I find it weird that these two aren't.
+ The Real Texas - An interesting take on Zelda-like games. Blocky western action adventure. It's on GOG, perhaps that tells you something.
+ SpaceChem - See Great Permutator. Also on GOG.
+ Will Fight For Food - RPG brawler or bum simulator? You decide.
+ Knytt Underground - Another good metroidvania, often overlooked. Perhaps because it focuses on exploration rather than shooting things?
Edit:
Could anyone confirm SpaceChem has been removed from the Humble Store? It no longer appears in my account, even though I have the soundtrack and the keys. They've changed the UI and obviously mucked up something because apparently I've magically purchased stuff for $0.0, even though my Paypal receipts disagree. But then I went to the store, and it's not there. I've tried googling, but no announcements anywhere. I hope this is just a simple mistake on their part, but I feel a little sick in the stomach knowing redeeming the damn Desura key just saved me from rebuying the game. I'm gonna go write them an email.
Can I ask for Great Permutator?. Thanks in advance.