Very good game I play a lot on my Vita when I don't wanna play a super hard game.
I have noticed that after the graphics changes the game seems to drop down to 50FPS on Vita at times.
A feature I'd like to see is some sort of arena to play against another player, akin to a kind of local play. I'm not sure how you'd implement that though, especially on PC.
Overall though very fun game thats completely free