An interesting game compared to the normal 'smash the alien' type. In Alien Break-In you have been left to defend Earth's uranium supply against the might of the Zargon fleet. As well as being shot at by aliens, a mothership is dropping pods and bombs. If a pod hits the ground it turns into a spider. The only way to destroy it before it kills you is to dig a hole which it falls into and then fill it up.
If a bomb hits the ground it creates a small crater, and when the hole is large enough an alient will land in it and mutate into another indestructible mothership. When ten motherships have been formed the Zargon fleet comes down the screen and invades - in other words, you've lost.
While loading, a tune is played. It is pleasant at first, becomes a nuisance and then a pain after three or four minutes. The instructions give you the option of changing the control keys to suit your preferred layout (or you can use a joystick), of halting the game if the phone rings, and of turning the sound off. Both sound and graphics are good.
The game provides nine skill-levels from 0 (easy) to 8 (horrendous). It's very addictive, though the only thing to aim for is a higher score. A worthy addition to your arcade library.