Pressure Drop is a one or two player, keyboard controlled, colour matching game.
The player(s) have a Chromagun which moves left and right on a rail at the bottom of the screen. The Chromagun fires different coloured rays for reasons which will soon become apparent. From the top of the screen ranks of coloured tiles descend. The player must use their Chromagun to destroy the bricks. They achieve this by shooting selected tiles thus altering their colour and tone so that each brick in the block is identical. The tile blocks are descending and unless they are destroyed they will hit the Pressure Ray. Each block that hits the Pressure Ray causes it to move up the screen thus shortening the time the player has to shoot at it, each block destroyed lowers it. Naturally all this is too easy to achieve if that were all there were to the game so along with the descending there are also various power-ups, a variety of brick types, and baddies.
The game is keyboard controlled and the action keys can be redefined