As climbing-around-the-screen type games go, this is tolerable. Particularly if you don't like spending a lot of money.
It's familiar stuff. You control Dave the Dungaroid in his attempt to escape from prison in which there seems to be just one prisoner (him) and a host of aliens.
So off you go, clambering around twenty screens, jumping between platforms, using lifts and so on. The action is not very fast, it's more a question of planning your route and good timing, rather than lightning reflexes. The main innovation seems to be the fact that you can fall as far as you like without killing yourself.
The graphics are a bit crude and blockish, but colourful and lively with busy screens. There's a jolly tune too, and a high score table.