TowerFall Ascension is finally landing on Vita on Dec. 15 and will be cross buy with the PS4 release. The Dark World expansion will also be releasing alongside the main game. TowerFall Ascension will run $14.99 and the Dark World will be $9.99.
Since TowerFall is a primarily a co-op focused experience, Vita owners will be able to do ad hoc multiplayer over local area WiFi. Cross save support will not be in at launch, but will be coming shortly after.