I have played it and honestly I really enjoy it. The map takes some getting used to and it is a bit short, but I have not finished it yet. The interesting part is that this combines a lot of different elements from other games. You have the classic Arkham feel/combat. Metroid-style exploration, and a semi-Mega Man level style in the sense that you can do certain areas whenever you want.
For example a friend of mine was like "How did you get past this part??" and I was like "uhhh...I didn't do that yet, but I did this part, have you done that?" Me thinking he was ahead of me, and he told me that he hadn't done that part yet. So we were both at parts in the game that neither of us had experienced yet. Not sure if that made sense, but I found that rather cool and unique.
EDIT: Between Batman, Rayman Legends, and Tearaway in the last few weeks for me, it's pretty awesome to have a Vita right now. Hopefully with the PS4 increasing Vita sales we'll see more and more games headed to the Vita.