Infiltrator

Now, this is simply amazing! So many cool ideas crammed inside this, I'm afraid I'll forget a couple while trying to summarize the game :).

What we have here is a top-down stealth game. As you see from the screenshots (err, I hope so at least ;)), you control a grayish blob trying to get past by bluish and reddish blobs that scan the area. If anyone catches you on their site, they come at you and start pounding you. You can plan how to lure them into traps though, including mines and holes, so you're not entirely defenseless. The feature I liked most though is that if a red blob catches sight of a blue blob, then they forget about you and they start attacking each other :D. To top this all off, in some levels you even get to play Sokoban, by pushing crates into the aforementioned holes in order to build bridges to get across levels!

A very ingenious and playable game! It gets the  award :)