QS Defender is a side scrolling shooter that although it is inspired by it, lacks many features of the arcade game Defender. This version is constantly scrolling left to right and there is no option to turn around and move in the opposite direction. The player can move up and down, fire and use thrust to increase the movement speed forward. There is only one enemy type and each one killed is worth 100 points. Enemies appear in waves. At the start there are just a few but as the player progresses it gets more hectic with up to eight enemies on the screen at once. The player has nine ships. When getting hit the screen goes black for a few seconds before it starts again with a clear screen and one ship less. Once all ships are lost the game has to be restarted through basic.