Steambirds Alliance

You pilot a bird aircraft in a war against the Feline Empire, taking on its enemies and cat bosses in an open-world shooter.

Fly alongside other players, avoid waves of bullets, and take on enemies together. The game also includes secret missions.

Permadeath raises the stakes, while unlocking and mastering different aircraft offers a progression path. The game lists 14 aircraft to unlock.

The supplied reviews fondly recall its MMO-style bullet-hell action, retro arcade feel, and distinctive aircraft aesthetic; some also praise how engaging it was to play. Several reviews mention that the servers are offline.