10 minutes in and I was hooked. I only have 2 hours on this game so far, but I highly recommend it.
Thanks Humble Bundle.
It's a rogue-like FPS bullet hell with randomly generated rooms and random bosses. ~8 upgradable weapons, 2 unlocked by default. About 10 perks(2 default). An endless mode and some other things I haven't checked out. The art style reminds me a bit of Borderlands. Interesting secrets to be found, illusory walls, high places, tight places, etc.. I think I reached a cap of having 9 jumps(8 extra in mid-air), which is fun and still not overpowered. It has controller support. The weapons are just upgraded automatically when you collect enough XP during a run, and it loses XP as you take damage, so your weapon can delevel if you suck it up. Each stage is timed, with a par time, though you can finish as slow as you want. You can collect money to spend on things you find. You can find many extra items that work as temporary increased crit chance, a weapon, etc.. Some pickups increase and decrease difficulty, add armor, damage... Modifications to the weapon can drop from enemies too. Blah blah blah. Just try it already!