Digi Invader is a classic game available in Casio calculator model MG-880 in the early 80s. It is a simple yet exciting game that challenges your brain and finger coordination.

The aim of the game is to destroy all the invaders approaching from the right side of the "LCD" before it touches the life indicator. Use the Aim button to match any number in the right and press the Fire button to destroy the invader.

There are 9 levels in 2 stages and each level has 16 invaders. Players must destroy all invaders within 30 ammo. The invaders will speed up when the level increased. When you completed level 9, you will be advance to stage 2. In stage 2 you also have 9 levels, the only difference is that the invaders in stage 2 are one step nearer to the life indicator.

You have 3 attempts for each level. Whenever the invader touches the life indicator you will lose 1 attempt. If you cannot clear the level within 3 attempts the game will end.