At it's core Prototype is a free roaming experience with a solid story backing it up. Players are put in the shoes of Alex Mercer, the victim of a genetic companies experimentation and he's on a quest to figure out who he is and who made him the freakshow he's become. Meanwhile a virus is spreading throughout the city infecting all the humans it comes in contact with and turning them into hideous monsters that Alex will have to deal with. Alex is mostly a good guy but he's also a monster and both good and bad folks are going to get hurt. That's the synopsis in a nutshell without spoiling anything.