Prototype is a lot of fun too, about halfway through, have most of the unlocks (PS3 version). But oh my god is this game messy. Messy control, messy combat, there are just some weird choices.
In general, this game does really really play like Hulk: UD, but with a disguise mechanism tacked on. And I really mean tacked on -- this is the stupidest stealth gameplay I've ever played. It's like if Hitman had a soundless, instantaneous body-removing kill, and all the guards are completely stupid.
For some reason (this is true of Hulk too) they chose to use the same button for running, dodging and air-dashing. Locking-on is infuriating -- at least the game slows down as you switch targets. Though you'll be doing a lot of hand-to-hand combat, you'll mostly be spamming attacks -- with nothing more than a diveroll, there's not much depth. There's also the fact that for some reason that though the game requires you to be dashing nearly all the time, you don't really have effective attacks that launch out of a dash (with one exception), especially not that use the current weapon. Or, until later in the game, from a jump, either. And very often the game is infuriating. Not because you'll die a lot, or it's super hard, but because you're trying to do something and the controls make you do something else. This is particularly true with the grab commands. Oh, and because there's no modes and everything has to fit on the controls, you have multiple different types of attacks on the same buttons, differing just by charge time. And some weird chords, like circle+square (remapping won't help, since triangle+square and triangle+circle are taken, too).
If you think environment traversal in Infamous is brainless or too easy, Prototype outdoes it. Hold down right trigger and you'll climb anything, at a run. It is fun, though, to run up a building, jump to the top halfway through, break into a glide then air-dash into another glide etc.
That said, it is a lot of fun. Going back on-topic, compared to Infamous I think it's a better open-world game -- side missions are just one of the ways to get experience, for instance, you can farm it other ways I think Infamous is better all-around, as a game -- the controls are tighter, it's more polished, the game mechanics are more thought out. I'm not entirely sure which one I like more, but I think Prototype may wear its welcome soon.
Edit: on the issue of power, I'd say they're almost equal, with an edge to Alex. I mean, Alex can take missiles to the chest and role around, and that really hurts Cole, but Cole has other, better ways to avoid such attacks. Cole by the end of the game also has a shield that can make him practically invulnerable from a single direction. The fact of the matter is that both can be nickle-and-dimed to death. Alex has a much easier time taking on big targets and tanks than Cole does against turrets and trucks for most of the game, but Cole has better crowd control. He's built around ranged combat and he faces enemies who mostly use ranged combat. Alex, on the other hand, is built around melee combat but faces a lot of enemies with ranged attacks (grenade-launching military are easily the most annoying enemies). Also, Cole can regenerate instantly from any electrical source, while Alex's options are more limited (you can consume regular troops, but when things get crazy any more powerful round will cancel your action). Neither of them can survive very long against the tougher enemies, but again Cole might have an edge.
