The objective of this game is to blast those plax out of existence by firing gel from the toothpaste tube. The joystick controls the tube - left and right are obvious, up and down change the direction of fire and the Fire button squirts the gel.
You have a fixed time limit - watch the counter at the top of the screen - to blast the plax to oblivion without losing too many teeth. If the "teeth" count gets to zero the pain becomes unbearable and you die a screaming, horrible death at the dentist's. Aaargh!