Galactic Intruders

Galactic Intruders is a 1-player space-themed arcade game for the BBC Micro.

The player must destroy the attacking waves of alien ships before they reach the player's planet. The player moves laterally at the bottom of the screen and fires vertically. Waves of enemy ships appear, and the player must destroy them all to proceed to the next round. Enemy ships can fire forwards or on angles. If the player loses three lives, it's game over.