The Jupiter Ace was a British home computer of the early 1980s, produced by a company set up for the purpose, named Jupiter Cantab. The Ace differed from other microcomputers of the time in that it used Forth instead of the more common BASIC.
Jupiter Ace - Released - 1984
Avoider is an action game for an unexpanded Jupiter Ace. The idea is to control your craft (0) to intercept the Jewelites (*) while avoiding the mutant asteroids (X) which will destroy your craft on impact. If you capture all the Jewelites, you move onto the next wave. Each wave is denser than the previous one.