In Amagon, your mission is to investigate a dangerous, monster-infested island. As Amagon, you begin the game with only a machine gun and a limited amount of ammo to protect yourself from the inhabitants of the island. Gameplay is an arcade style platform game with six levels, each with a variety of creatures and a large boss at the end. When you destroy an enemy, a power up will sometimes be left behind. Collecting these can give you extra points, an extra life, more ammo, or a mega key. If you have enough points and collect a mega key, you then have the ability to transform into Megagon. In this form, you are larger in size, can jump further, and have increased strength. You start the transformation with an amount of mega points; each time a creature injures you, points are lost. When all of the mega points are gone you will transform back into your normal size.