The challenge in each level of Puzznic is to maneuver a selection of blocks into place so as to clear them all, by making them make contact with blocks of the same design. You control a cross-hair, which can move a block left or right, which can cause it to fall if there is no block under the space it would occupy.
The Game Boy version of Puzznic features a different set of puzzles than the other versions of Puzznic. There are a total of 128 puzzles to solve.