There are two modes: blue when you can aim, and red when you cannot. Use the arrow keys to adjust both the direction and speed, indication by the position of the target. Alt resets the target. Ctrl moves.
A remote and highly radioactive facility. A remote and remote-controlled robot. Interplanetary hero Commander Keen guides his newest invention, the sphere-o-droid, across a toxic, inhospitable environment. He must acquire the incredibly valuable Giga-Positronium atoms before the entire reactor building overloads and is destroyed...