After the poor reception of SOCOM 4, and some subsequent post-release downsizing, Redmond-based Zipper Interactive is setting its sights a little smaller for its next outing. And by smaller, we mean PlayStation Vita-sized. Unit 13 isn't the thirteenth title in some entirely unknown and impossibly long-running edutainment series; instead, it's the name of Zipper's dual analog-powered portable shooter.

"Fast action, on-the-go gameplay was a key goal for the Unit 13 team," Zipper president Brian Soderberg writes on PlayStation Blog. "Missions come in a variety of sizes and difficulty. Some are smaller bite-sized battles; others are longer, more challenging, multi-objective missions that are a good test for any skilled shooter fan."

Bite-sized gameplay isn't the only thing Zipper adopted from the world of mobile games; the Vita's WiFi and 3G functionality keep "players up to date on leaderboard positions, new 'Daily Challenge' content, new unlocks, shared High Value Target missions, and challenges from friends as they move past you on the leaderboards."

Unit 13 even features co-op with accompanying voice chat, playing into the Vita's console/portable hybrid approach. Perhaps a tad more worrisome: "it's available right around Vita launch," Soderberg says, and this is the first we're hearing of it. We're trying to stay positive here.

This article was originally published on Joystiq.