In Blobbers the player controls a mobile laser unit trying to defend itself from the Blobbers, fearsome, giant, amoeba-like creatures that will devour anything they encounter. The mobile laser unit moves grounded to the sides of the screen area. The Blobbers will also move along the same sides, and as the laser gun can only shoot straight forward, the mobile laser unit has to be in the opposite side of the screen to hit the Blobbers.
A Blobber borns as a harmless small yellow spot, growing to a bigger and purple mass, to a bigger and white one until it reaches its red adult form. Only when it is red it can do harm to the mobile laser unit, if they are of any other color, they will only stick to the mobile laser unit until it moves and releases itself from the Blobber. As the time passes, an adult Blobber will multiply, releasing a new small yellow spot which will eventually grow into another adult Blobber. When Blobbers are hit, they are reduced to the immediate previous stage of development (from red to white, then purple, then yellow, then deceased).
In the middle of the screen, moving blocks called Magic Transporters move up and down randomly. They are called Magic Transporters because they can be used to transport the mobile laser unit from one side of the screen to the other, if the mobile laser unit moves onto one of them while they touch the top or bottom of the screen. The Blobbers will also be transported by them. Also, they are impenetrable by the laser gun, meaning the player will only be able to hit one Blobber when there are no Magic Transporters in the laser's way.
The Blobbers will become faster every 90 seconds until finally reaching the mobile laser unit's speed. The player has only one life and no continues.