Gravitron

Gravitron is a single-player action game.

The player controls a spaceship that can move in all directions, while the force of gravity constantly pulls the ship downwards. The ship fires vertically upwards, and at a 45 degree angle downwards to the left and right. The player must destroy enemy installations. They start with 4 sips, and if all are lost, it's game over. There are 20 levels of difficulty, and at higher levels enemy installations fire more frequently. As well, on higher levels, saucers will approach rapidly from the side of the screen after a quick warning, preventing the player from staying at the top of the screen.