Good shooter with excellent skill adaptive AI. Only 3 weapons though and short but not bad for 20 bucks.

User Rating: 8.2 | SiN Episodes: Emergence PC
I bought this for fun. 20 bux. And it used the Source engine. I think, haha. Anyways, good deal for 20 bux and it has the original sin in it (if you want some old school 3D graphics).

It is short but for the price, it isn't that short. There are only 3 weapons but each as two firing modes. The AI is awesome though. If you die a couple times at a certain part, you'll go through and find a few less enemies or all the enemies you kill will drop health. I really like this option in a game because it takes away the frustration and you can always turn up the difficulty and the AI adjustment difficulty.

If you like FPSs, its worth a buy. Oh, and for the guys, this game has the best boob bobbing I've seen in a game to date. Very realistic. LOL!