I took the plunge and bought my first PS mobile game, and I have to say that Aqua Kitty: Milk Mine Defender is kind of awesome! My only gripe is that the game is a little bit harder than it looks, but the art is crisp, the controls are tight, and the game is fun overall.
In terms of replay ability, there is a little campaign mode with levels that have you defend your cat friends and milk mines from enemies, and there is also an endless mode with everything vs. yourself that's thrown in just for kicks.
For $3.49, the price is slightly higher than I would normally pay for a game, but I have so few vita games that I just wanted to take a chance. I recommend this game to anyone who has a Vita! 4/5