Prototype should be a great game, but...
Unfortunately, it is let down by dull and uniform-looking environments that all seem to be the same colour, and therefore nothing stands out. In a game where you spend a lot of time travelling back and forth to find and complete missions, this really is a big deal. And there is A LOT of running around.
It's sad because everything else is there - great combat, loads of interesting upgrades and powers, interesting cutscenes...but the blandness of this version of post-apocalyptic New York drags the game down. I know it's not supposed to look pretty, but it should be striking - other games have managed to devastate Manhattan in a way that is visually cool, Spider-man Web of Shadows for example.
Prototype should've been a fantastic game, but just manages to miss the mark and descends inevitable into tedium.