Ostriches are weird creatures. For starters, they're birds, but they're frickin' massive, weighing as much as two humans and standing at least a foot taller. Second, they're one of the very few land creatures that exclusively walk on two legs. Naturally, this makes them the perfect subject for an online co-op exploration game!
Ostrich Island from MeDungeon sits on the fence between a serious game and a let's-just-run-around casual game. The central idea is you and your friend play as an ostrich running around lush tropical islands. There are sights to see, items to collect and things to discover, and you can jump, kick and peck your way around it all. There are some light RPG elements and unlockables to keep you hunting, but apart from that, it's all about the ostrich life.
Each island you explore is filled with secrets with the only limitation being the constantly rising water level. Ostriches aren't penguins, you know. The game focuses on that lovely co-op experience of "hey, I see a secret, let's spend the next 20 minutes trying to get it!". Simple, but remarkably effective. And go ahead, try not to giggle as you hobble around the island on your wobbly ostrich legs.
Ostrich Island is currently available for PC via Steam. It supports two player online co-op and even has a handy two pack for a nice discount.
Source: Store.steampowered.com