ClassiCube
Click the button at the top right of the game to toggle fullscreen on and off.
Press Esc to show your cursor.
About ClassiCube
ClassiCube is a sandbox block game inspired by Minecraft Classic. Visit their server list to play with other players. Please note that you'll need to sign up for an account there.
Controls
More Games
Check out Eaglercraft and Minecraft 1.5.2.