An interesting story and surprisingly fun game-play help make Prototype a really fun sandbox game.
Story:
New York City is infected by a virus called "Blacklight" and you, Alex Mercer were given extraordinary powers do to it. However, you have NO memory of what happened to you. Now your goal is clear, stop the virus and find out who you were. Alex Mercer himself has grown into a favorite character of mine, and I personally found the story to be really interesting.
Game-Play:
Prototype is a sandbox superhero game. New York city is your playground. The powers you have are what makes this game awesome. I can't think of many other games where you feel THIS awesome. You can turn your body into a variety of different weapons, consume living beings and take their shapes, gun it full speed (almost Sonic like speed), run up building, pick up cars and chuck them half way across the city, hell pick up a gun. There is SO much fun to be had in this game that it NEVER gets old.
Graphics:
The game-play and story may be awesome, but these graphics aren't. The game looks really dated, but Mercer himself looks good. It looks like a 2006 release, which is a shame,
Sound:
The voice acting is surprisingly solid actually. And the soundtrack is quite good. Not much more to it than that.
Overall:
Prototype is one of my favorite open world games. An interesting story and game-play make this a really fun game, and it's definitely worth a pick-up.