Jumpjet Game

Jumpjet is a 2D side-scrolling shooter game for DOS, created by Monte Variakojis and released by Montsoft in 1990 as shareware. It is said to be a relative of the older game Defender. The player controls a little Harrier-like jet that can gain or lose altitude without moving side-to-side. The player fires missiles at his targets. There are four levels, each with a different objective. There is also two bonus levels that can be accessed with a high enough score in levels 1 and 3.
Each game uses different controls, most DOS games use the keyboard arrows. Some will use the mouse , "Alt" ,"Enter" and "Space bar".