Xenon

Xenon is a 1988 vertical-scrolling shooter computer game developed by The Bitmap Brothers and published by Melbourne House, then part of Mastertronic. Xenon was superseded by Xenon 2: Megablast in 1989. The player takes on the role of Darrian, a future space pilot who is called into action by a distress call from his superior on a nebula space station. For some time now, humanity's colonies have been under attack from mysterious and violent aliens, the Xenites, and it's finally time for Darrian to fight them. Unlike most scrolling shooters, the player can move in any direction instead of just straight ahead. The player vehicle has two modes: a flying plane and a ground tank. Switching between the two modes can be done almost at any time during the game (except in the middle and end of the level at bosses and in certain levels where a specific mode is mandatory). Destroying some enemies unlocks power-ups that the player can use to improve his ship.