The game is based around growing the cactus. The goal of each level is to push a set of potted cactus plats into designated holes.
The cactus grows from the active head to the next grid intersection (corners count as intersections). Some grid intersections are inside walls, should the head move into a wall instead then the head will remain in place and the rest of the cactus body will shift. Should the body hit a wall the move will fail and the cactus will not grow.
Thick lines on the grid indicate forced movement. The cactus will continue to grow along the line should the head hit a thick line. The head can hit a thick line in the middle, this will cause the cactus to grow in all directions, creating multiple heads.
Heads will fall asleep if they end up away from a grid intersection. They will wake up again should they end back on a grid intersection.