Monster Max is an aspiring guitarist who is compelled to save the world from a music-hating invader. In order to proceed, he needs to solve a series of puzzle-based isometric dungeons, collecting or destroying a specific object to complete the stage. After each floor is successfully cleared (three stages apiece), he ascends to the next, more difficult set.
Max is limited to basic movement in any stage initially, but can collect certain power-ups that increase his ability to explore and proceed past traps and obstacles. Usually, these items need to be found before he can complete the stage's objective. In a sense, it employs the Metroidvania system of incremental progression, except Max needs to collect these items each time and not all items appear in each stage. These items include:
Boots - Allows Max to jump, to get over low obstacles.
Duck - Allows Max to duck, to get through narrow gaps.
Bag - Allows Max to collect blocks in the level, to use as mobile platforms.
Sword - Allows Max to attack certain enemies, removing them.
Super Spell - Allows Max to destroy all enemies on the screen, including those immune to the regular Spell and Sword. The Super Spell becomes the regular Spell afterwards.
Spell - Allows Max to destroy certain enemies.
Forcefield - Makes Max invincible but unable to move, useful for standing on moving platforms that travel past deadly traps.
Stars - Allows Max to take a hit once without dying. They can be stacked.
Spring - Allows Max to jump twice as high as usual, though disappears after so many uses.
Map - Reveals the entire map for that stage.
Gold Bars - A bonus item Max can collect for extra points, should he finish the stage.
Monster Max, though developed after the advent of battery back-ups for Game Boy games (notably The Legend of Zelda: Link's Awakening), does not include this feature. Instead, the game's progress is saved with a password system the player is required to record.