Galaxian is a free remake of the popular 80's arcade game in full screen. You can download all 71 of the Crozza Remakes here.
This remake is done well complete with the familiar, yet annoying sounds. Gameplay is simple. Use your arrow keys to move left or right, space bar to fire, and F4 for full screen. ESC will bring you back to the menu screen as pause or exit.
Galaxian is portable, just extract, run, and play.