A fun shooter for a reasonable price.
Sin Episode 1: Emergence
Gameplay - The gameplay is similar to Half-life 2. There are no third-person cutscenes meaning that you are always in control. There are only 3 weapons, but they all have a powerful secondary fire mode. I like the magnum's secondary fire, where it shoots a depleted uranium round which can penetrate through most walls and through several enemies. Your enemies include mercenaries, chain-gunners, flying robots, and mutants. My favorite has got to be the mercs with jetpacks. It's fun to shoot their jetpack and see them fly around like a deflating balloon in the air before exploding and plumetting to the ground as they scream.
Graphics - Emergence uses the Source engine which was used in Half-life 2 and other Valve games. The characters are very detailed as are the environments. Like Half-life 2, Emergence uses the Havok physics system which provides more hilarity as you blast away your oponents.
Sound - The sound has improved greatly since the first Sin game. Voice acting is top notch and not cliche at all. I like how you can hear the soldiers yelling in the distance as they get ripped apart by mutants...
Value - The singleplayer game alone is worth $20. Multiplayer and a SDK will be free and released before Episode 2 comes out.
Verdict - Get this game if you love challenging shooters and big boobs.