The object of Astronut is to push three blocks onto matter transporters at the bottom of the screen but there are many things to stop you. Unlike Software Projects other games, you don't have the option to jump, you rely completely on two little erupting volcanoes which will throw you up to the first bridge or ledge you reach.
You can drop bombs which will kill the enemies but there is a time delay before they explode making it difficult to time the destruction.
Astronut contains fifteen screens, every one better than the next. If you can't clear a sheet, you have the option to go directly to any other after the game.
Graphically it is excellent but unfortunately the instructions don't tell you which keys to use. This is one game I will add to my collection.