City of Xon!

Evil Xon and his forces are on a ridgetop encircling a valley full of his subjects. In this isometric shooter you control a craft moving it up or down, and the aim is to destroy as many of Xon's armaments as you can to reach Xon himself and bring him to justice. You have the choice of two weapons, a disruptor (more powerful) or a phaser, and you have the choice of turning your armour on and off. Moving the craft, using weapons, or having your armour on uses fuel shown by a gauge but fuel can be collected with a grappling hook or turning part of your score into fuel. If you crash or run out of fuel then it is game over. Once you have amassed 300000 points or played for two hours, you have the chance to grapple Xon with your hook.