Neutroid

Neutroid is a 1-player arcade game for the TRS-80.

A small neutroid bounces about a grid, and it can be redirected at any of the grid points. The goal is to crash the neutroid into the protroids that circle about the outside of the grid. If the neutroid crashes with the high energy outer wall, it is destroyed. The player advanced to the next round when all protroids are consumed. The neutroid speeds up as the round advances. Vertical and horizontal high energy regions briefly appear on the outer walls, and these supply a bonus if hit. On higher levels, bouncing antitroids can destroy a neutroid. It's game over if all neutroids are lost, and the player gains an additional neutroid every 5000 points.