Highway encounter has you controlling a dalek like robot in order to push a bomb along a straight highway so that you can destroy the alien base at the end. The aliens however are not taking this lying down and have set up mines, obstacles and various enemies along the way in order to stop you.
The mine itself is automatically pushed along by your spare "lives" in the form of other robots like yourself that just move forward all the time until they hit an obstacle. You only have control over one of the five robots at once and must safely clear the way for the remaining robots. You can rotate the robot left or right and accelerate or decelerate and also fire your gun in order to destroy objects.