Sometimes, if you play on this stage with the Vita, the sound will disappear completely. You won't be able to hear the fighting sounds or anything. It's like the game's on mute. Then, eventually, you may hear a jet zoom by. Also, eventually, the sound will come back, but then leave again.
Please address this bug, SuperBot/BluePoint.
(And guys, please bump, thanks!)
It may happen again to you :/