Monster Tale is an action/exploration platformer with RPG and virtual pet elements. Ellie, the player character is equipped with a long-range projectile in form of her plasma-firing bracelet, and a short range attack via a deadly purse. Along the way she would also acquire various abilities such as a roll, wall-slide, uppercut and many others. Her health can be upgraded via collecting heart containers.
While the player character moves and fights monsters on the top screen, the bottom screen of the system is most often occupied by the monster sanctuary, which presumably exists inside Ellie's purse. There - Chomp spends his time interacting with objects left behind by vanquished foes. Each object yields experience points that level up Chomp, and once he reaches a certain level, he is able to shift to another form. Each of the many visually distinct forms of Chomp have special attributes, like higher attack, defense, agility, endurance etc. In addition - each form also has two unique special skills, that once mastered can be executed in any other form.
Ellie can summon Chomp up to the upper screen with a press of a button. When topside, Ellie's pet will attack enemies and interact with certain out of the way switches and triggers, all the while his life gauge will drain constantly, and even faster if he comes under attack from foes. Once the life gauge is empty, Chomp will faint and return to the sanctuary screen where his life will recover.
Generally, most of the in-game action happens on the top screen, but some enemies, bosses, and even puzzles will invade the monster sanctuary and require Chomp's direct intervention via touch-screen. In these cases the player might be required to return his pet to the sanctuary, if he's been summoned topside, and point him to the source of danger or interest via a touch of a finger or a stylus.