Old One
Arcane
Machinarium
I really liked this game when I was a kid, cyberpunk+demons-->it's so fucking edgy. It's predecessor - Bloodnet would also fit in here btw.
I was actually planning to mention this one in teh Lost & Forgotten thread. As far as the visuals and atmosphere go, think of side-scroller equivalent of Souls and KF games.
(also, curious that certain game from whence my nickname originated wasn't mentioned yet)