Denarius

The Rignalian race have decided that they want to colonize the planets of the Solar System and their moons. To help support their life-forms they need pools of chlorine to survive, and so in their space arks they have placed the pools in various cities. You have been tasked to fly your space fighter over 16 infected cities, blasting the alien crafts and collecting as much of the chlorine as possible to save the Solar System.

The game is a top view vertical shooter, with the screen scrolling constantly upwards as you blast and collect. As well as the enemy crafts to blast or avoid, you also need to avoid obstacles, or you lose one of three lives. As well as your laser, you can activate one shield for a limited time for each city. On the surface of the city, the chlorine pools are small squares in clusters, and you need to fly over these to collect them. The number you collect is turned into points at the end of the level

When you survive a city, you then move onto a bonus level, which sees walls of gas move down the screen towards you. There is a gap that needs to be flown through for each wall, or if you touch the wall then the bonus level is over, and it's onto the next city. A joystick is used to control your space fighter.