Sega have announced Phantasy Star Nova exclusively for the PS Vita. It’s a primarily single player game developed by Tri-Ace set in the world of Phantasy Star 2, which it will coexist with on the PS Vita. The game can also be played co-op with up to 4 players online.
Apparently the game will feature really big enemies. Screens and video will be available at TGS, however the game won’t be playable.