The sequel to Rocketbirds: Hardboiled Chicken , Evolution takes place years after the previous game. Dreaded totalitarian leader Putzki is still alive and kicking, and it's up to Hardboiled to stop him. However, he gets sucked up in a increasingly bizarre conspiracy that involves alien owls and people being turned into food.
Gameplay in Rocketbirds 2: Evolution is similar to its predecessor, but with a greater focus on combat and fewer puzzles. The player can now aim 360 degrees, jump, shoot, run, and perform other actions simultaneously. There are dozens of weapons at the player's disposal, ranging from handguns to rifles, flamethrowers, and miniguns. The levels are much larger and more open-ended than before, allowing for secret areas containing hidden items.
A new feature in Rocketbirds 2: Evolution is the Rescue Mode, a 4-player online/offline co-op mode where players control the budgie commandos from the previous game. Their objective is to rescue other commandos across four randomly generated themed levels. Players can upgrade themselves by collecting costumes and buying weapons at shops.
The game also includes stereoscopic 3D, enhanced voices in English and Japanese, improved graphics, and a new soundtrack by New World Revolution.