Defend yourself from horizontally moving aliens who fire on your ship. Defend your fuel tanks from walking machines who fire missiles into the air.
Technical:
The game has a voice simulation. As it was created in 1981, the quality of the voice is not all that great but for the time it was an innovative attempt to stand out.
1 Player Start 1
2 Players Start 2
Coin 1 5
Coin 2 6
P1 Left LEFT
P1 Right RIGHT
P1 Button 1 LCONTROL or Mouse B1
P2 Left D
P2 Right G
P2 Button 1 A