Metal Mutant uses a side-view perspective across connected areas filled with platforms, enemies, barriers, and hazards. The main objective is to explore the world, survive encounters, find a route forward, and defeat or bypass obstacles using the appropriate form.

The protagonist can transform between a humanoid robot, a dinosaur-like combat form, and an amoeboid form. Each form has distinct attacks and movement capabilities, so progression depends on switching forms at the right time rather than relying on one universal attack. The game is structured around exploration and screen-by-screen advancement rather than conventional experience levels or equipment upgrades.

Learn the purpose of each form before entering unfamiliar areas. The humanoid form is useful for general movement and interaction, the dinosaur form is suited to direct combat, and the amoeboid form can handle situations that the other bodies cannot.

Advance carefully and observe enemy patterns, hazards, and possible routes before committing to a transformation. Conserve safe opportunities for changing form, since choosing the wrong body can leave Metal Mutant unable to cross an obstacle or survive an encounter.