Demons Of Topaz is of Australian organisation, and is basically a ladders and platforms game with added boomerangs. Without going into the overcomplicated storyline, you use keyboard or joystick to control your character Ozzie as he meanders through an asteroid comprising dozens of interconnected screens.
Your descend on the first level (rather slowly) and you can walk left and right to explore, or rather you can make the screen scroll right and left, though to get down to move of the asteroid's eight levels, you have to find a gap in the floor which you can fall through to seek out the seven legendary Sacred Crystals.
The levels are made up of the usual combinations of walls, gaps, ladders, moving walkways, floors that collapse beneath you, and so on, and you must thread your way through these while avoiding the killer plants which seem to grow everywhere on the asteroid. If you find a crystal you have to take it back to your ship before setting out to search for another one, which also replenishes your air supply.
There are nine skill levels, and only on the harder ones do the demons and other nasties make an apearance. These you can see off by firing your boomerang, and one nice feature is the control you have over this. It always returns to you, so if you thwor it then climb a ladder or jump you can alter its trajectory to maybe clonk a meanie on the way back too.
Overall, however, Demons Of Topaz is a disappointment: it's slow, there's precious little sound, the graphics are average and the control you have over the character is also not quite spot-on.