Halloween Monster Puzzle is a block-puzzle game that's similar to tile-matching games like Tiles of the Simpsons. It features the heads of monsters (frightened white ghosts, green Frankenstein monsters, grinning jack-o'-lanterns, one-eyed red devils and smiling gray skulls) instead of blocks or tiles. The player's goal is to remove all of these monsters from each graveyard playfield across 60 levels.
The player can only remove three or more adjacent (below or side-by-side) matching monster heads at a time. When the removal of the heads forms gaps, all of the remaining heads drop and slide toward the center from the left and right sides. The player must take all potential movement into account before they remove heads to prevent situations in which they accidentally leave behind one or two matching heads that they then can't remove from the graveyard playfield. That said, the game allows them to reload a level without any in-game fees or penalties.
Halloween Monster Puzzle also features chained and locked heads. The player must remove these bindings before they can remove the monsters. If applicable, the player must first remove shields atop the chains. Some levels only feature chains.
This aspect of the game makes play challenging because shield and chain removal sometimes makes nearby heads disappear as well. When this happens, the number of available matching heads can drop too low to finish the level.