Prototype is a good game until you realize its lack of variety and sometimes frustrating combat mechanics.
Some virus has turned a majority of the civilians of modern day Manhattan into zombies. You play as Alex Mercer, a man who also got infected yet gained superhuman abilities for a reason I never quite understood. The military is trying to hunt you down because I guess Alex is their science experiment gone wrong. The story itself is pretty convoluted at best and mainly serves merely as a reason for you to go around killing people. All the characters are lifeless, including Alex who isn't sympathetic to anyone other than his sister and only cares about killing the people who accidentally gave him his powers, despite him murdering hundreds of innocent civilians along the way. The only real way you can make any sense of it at all is to look at the "Web of Intrigue" menu which basically binds different "visions" Alex experiences throughout the game together. I hardly ever went to this menu because, well, I didn't really care for the story much in the first place, so why bother?
For the first couple hours, you'll find this game to be a blast. Right off the bat you're given an impressive selection of moves and powers to use at your disposal. You can run up walls and buildings, jump high and far off of walls and such, and even glide in midair for short distances. During combat you can devastate most enemies merely by hitting the X button to cannibalize them. Yes, you can actually do that. And you'll be doing it quite often, too, since it's the only efficient way to replenish your health bar. It's satisfying to rip someone's head off with your claw and watch their flesh and gore bind with Alex's body, or to just slice someone into multiple bits with one slash. Also after you cannibalize someone, you have the option to take on their appearance, which is helpful if you're disguised as a soldier and your mission is to infiltrate a military base. Alex can also morph his hands into sharp claws, a devastating hammer or ropes. These are just the things I can remember off the top of my head, and you can purchase upgrades and new moves with the experience points you gained from combat experience or side missions. Even tough there are a ton of moves, you'll most likely just pick a favorite and stick to it.
Despite the variety in combat, Prototype has a complete lack thereof everywhere else. This is partly due to the banal version of Manhattan you're put into, since most buildings look identical and there are few actual landmarks to be found. The city isn't very colorful either; you'll mainly see dreary gray, black and dark yellow and red throughout the city. But the main reason the game is repetitive is because of the missions. The mission structure is pretty straightforward--arrive at a base (usually a military-controlled one at that), kill everyone or everything there and then escape from the vicinity. It doesn't help that mission locations sometimes look identical to one another. Occasionally you'll be forced to drive around in a military tank and blow a building up, which isn't that much of a step up from the other missions, but then you'll have do that over again a few missions later. There are some escort missions boss battles thrown into the mix even they too follow a similar pattern to one another. So to sum it up, each mission ends in almost the exact same way following almost the exact same pattern in almost identical-looking places. The side missions aren't much better. Most of them are different variations of killing everything on screen, but some such as checkpoint races make use of the gliding feature. Unfortunately, you'll probably have earned enough XP points from the missions and had enough of killing people as well so the side missions are best left alone.
Quite possibly the worst thing about the game is when the combat begins to get chaotic. Regardless of whether you're in a mission or not, whenever you raise your "military wanted level" up far enough, you'll get dozens of soldiers, tanks and several helicopters thrust at you at one given time. This reminds me a bit of the Matrix movie. Sure, when Neo and others are in the Matrix they have superhuman abilities, but then Agent Smith shows up and then they're forced to run away from him and the other agents because they can't beat them, at least not in that movie. The same thing applies here: Alex Mercer can kill all the soldiers and zombies he desires, but when military helicopters arrive at the scene, it's time for him to run or take shelter. It's nearly impossible to defeat helicopters in this game without throwing objects up at them, which is also nearly impossible because they'll drop air strikes on you, basically leveling out an entire block. These situations (which happen a lot) make you feel powerless in a game that's seemingly all about power and abilities.
From a visually standpoint, the game doesn't look all that great. As I said before, the city mainly looks identical with bad coloring, and the buildings can look a bit blurry with bad texture design. Cars look too blocky, the draw distance is considerably limited and the only thing that really looks good is the gore effects. Cutscenes look OK, but it's not like they're something we haven't seen before. The audio isn't outstanding, either. All you'll mainly hear are rather loud explosions and tons of gunfire. The voice acting during cutscenes is actually good, but it doesn't make much of a difference when you can care less about the story.
The sheer amount of power and superhuman abilities at your disposal do make up for some of the game's problems...until, of course, the helicopters show up. The rest of Prototype feels unfinished, since a lot of the effort seems to have been put into making you feel very powerful (again, until the choppers appear) and the missions a mere afterthought. Still, I managed to enjoy Prototype for what it is: a mindless yet fun action game/gore fest with a story you shouldn't take seriously but also with enough explosions and fighting to keep you interested...at least until the helicopters arrive.