n single-player mode a single Scratch Cat enters a room, from its walls pours an endless supply of rats. The player must catch and eliminate a certain number of these before a door will appear taking them to the next room. Each area has several rooms, in its particular theme.
The object of the game is to clear each level of the allotted number of rats and continue on to the next room. The player uses a loop-like lasso called an 'Eraticator' to catch the rats. With them trapped the player then must take the rats to the 'Destructor Pad', located in each of the rat-filled rooms, to dispose of them. If the player is bumped by a rat or other damaging item in the room, the rats can escape the trap until they've been eliminated by the 'Destructor'.
At the end of each level, the player receives bonuses reflecting how well they had done. Such as receiving "Damage Bonuses" for how much the room got damaged (the less damage, the higher points), time bonuses (the less time taken, the higher the bonus), and perfect bonuses (if none of the items in the room got destroyed, the player obtains these points.)
In most of the rooms, various power-ups will occasionally appear to help the player, they can also be found in treasure chests, which require eliminating a certain number of rats at the same time. These power-ups allow such things as, some of the damage done by the rats to be reversed, allowing the player to avoid taking damage for a short time or get back one energy that they lost. Other effects are making the player able to grow large and stomp on the rats, to run much faster, or make the lasso bigger. There is also bate to attract the rats to one location. Besides these power-ups, there are also power-downs, that are released by the rats when they destroy a box or other things. Resulting in the players controls being reversed, rats being ejected out of their trap, or slowing down, and other such features.
Later gameplay also introduces things like switches, fans, laser beams, and teleporters. Thus, adding puzzle elements to the game. Requiring the player to figure out how to use the various devices before the items in the room get destroyed.
The rats themselves can hurt the player if they touch them. They can also jump out the lasso if not stunned by a claw swipe or other type of attack. They can climb up large walls, and be duplicated by a 'Rat Copier'. A special white rat is in several rooms, these have the purpose of only getting to a Mutation Pad and then transforming into a monstrous rat that hunts down the player.
At the end of each area, there is a boss that the player must defeat. However, the Scratch Cats can't harm the bosses directly. The player must figure out how to harm the boss, in most cases by using their attack against them.
In multiplayer mode the gameplay is almost identical, but with a few additions such as a 'Gold Rat' worth more points, and a few additional power-ups/downs. The players can also choose a special mode which allows them to go after rats of their own color.