The first Rocketbirds was a solid, non stop shooter that didn't lack depth. It had some room for improvements though and that's exactly what Ratloop is doing with the sequel dubbed Evolution.
In it, you'll find an enhanced only support with up to four players online or offline, you'll also be able to customize your characters with a wide variety of silly outfits.
To add more meat to the game, you will also find a new rescue mode and the dojo, the place to kick your friends' butts in PVP.
The game's humor is still present as attested by the latest gameplay trailer:
It's out on April 26th and is cross-buy compatible.