From the readme, this is Tetsuzi Usude's first game, and it comes off a reasonably polished. You try and make your way through a maze full of hostile robots. There appears to be different guns you can pick up (although the animation remains the same) as well as mapping terminals and some other features.
Movement/rotation continues after a key press, making the controls a little awkward. The 5 key on the numpad will halt this, until your next keypress.