Xenon

Xenon is a 1988 vertical scrolling shooter computer game, developed by The Bitmap Brothers and published by Melbourne House which was then owned by Mastertronic. Xenon was followed in 1989 by Xenon 2: Megablast. The player assumes the role of Darrian, a future space pilot called into action by a mayday report from his superior on a nebula space station. As of late, the colonies of mankind have been under attack by mysterious and violent aliens called the Xenites and it is finally time for Darrian to engage them. Unlike most scrolling shooters, the player can move in any direction instead of straight up. The player craft has two modes, a flying plane and a ground tank. The transition between crafts can be initiated at almost any time during play (except during the mid- and end-of-level boss sections, as well as certain levels where a certain mode is forced), and the mode chosen depends on the nature of the threat the player faces. Destroying some enemies released power-ups the player could catch to enhance their ship.