What's wrong with it? I'm going to start on it in the next week or two.
It has an auto-save feature for checkpoints. It can be a bit weird, though. You'll kill every enemy, and if you die it won't register any of your last actions as a checkpoint and you'll be sent back way farther than you were at. This is rare, also the game is ridiculously easy even on the hardest setting so you won't be dying too much.
It's kind of a miracle of a game. I can't believe some of the visuals they got to work on there. It's also a fucking battery murderer. Lowest brightness settings and offline, and the thing still drains my vita's charge like nothing else. Playing online multiplayer is ultimate killer of it as well.