Activision is promoting Prototype 2 with a tie-in iOS game, released ... several months before Prototype 2. Protoslice is a puzzle game from Twitchgames, based on its game Slice, in which you move a bunch of James Heller's Blade Arms out of the way of on-screen buttons.
If you accidentally touch the sharp parts of any of the blades, you'll be sliced! Hence the clever name. Protoslice is out now, for a price appropriate for its promotional nature: nothing. So there's no reason not to check it out -- especially if you want something Prototype-y to do between now and April. Unless you're sensitive to images of you getting sliced, in which case you probably weren't going to check out Prototype 2, either.