Phoenix
Phoenix is Atari’s 2600 version of the 1980 arcade shooter, made under licence from Amstar Electronics and programmed by Mike Feinstein and John Mracek of General Computer Corporation. It came out in early 1983 and, like the arcade game, mixes very different stages: diving small birds, huge birds that regrow their wings, and an alien mothership. You can play it here in your browser, with nothing to install.