High Resolution Invaders

High Resolution Invaders is a Space Invaders variant that was one of the first games to use high resolution graphics on an unmodified 16K ZX81. The gameplay works just like in the original with the player moving left and right while shooting at the aliens that move back and forth across the screen. The aliens drop bombs that have to be avoided and four shields offer some protection. The aliens differ from the arcade game in that they only move horizontally but never descend. The player has three lives and the game ends when they have been used up. Before starting out it's possible to choose the firing rate for the player's missiles as well as for the aliens bombs, from one to six. The game can be played by one player, two players taking turns or two players playing simultaneously.