This game doesn't fit any preconceived categories.
It is really a cross between an adventure, a minefield and a maze game. You wander around a captured spaceship looking for weapons and keys whilst avoiding invisible aliens.
The stated aim is to survive and to set the self destruct mechanism so that the aliens are prevented from reaching Earth. But simple survival was my main problem.
The game gets rather boring after a while, despite the six play levels. If you are unfortunate enough to find an alien before any weapons then the game is extremely short and rather pointless. The real problem is that the game relies far too much on random factors and not enough on skill for lack of it!)
The graphics are good, although to make the playing area larger the characters are rather small. I especially like the advancing alien showing its teeth.
The choice of control keys is, however, most strange and could be much improved. Since the game is written mostly in Basic, response time is rather slower than I would like. The cassette is well-priced for its contents and should appeal to younger players.