My Vita froze the first time playing it, basically killed the system and it needed a complete reboot (from the debug menu). Second time playing had no troubles.
The game needs more levels in the demo, I had fun in the first level but I think I need another level to see if I'll truly enjoy it. That said, I don't like Zipper games anymore; as a developer they have gone downhill to the level of Infinity Ward or the Sonic team.
I think if all those levels were actually in the form of a campaign or story mode then I'd be all over it but because it's set out individually it doesn't have me grabbing for it. I was really looking forward to it as well. The lack of online multiplayer is very disappointing as well, they could've done a SOCOM style multiplayer for the game but instead all we have is co op.