Amagon, developed by Aicom and published by American Sammy, is a side-scrolling platformer and run-and-gun in which the player controls a particularly fragile marine by the name of Amagon. He is stranded on an island when his plane crashes down and must make his way across to where a boat can be found. Between him and the boat are all the island's hostile inhabitants.
Amagon was originally released in Japan as Totsuzen! Macho Man and that version was published by Vic Tokai instead.
Amagon must make his way to the end of the stage and defeat a boss before moving onto the next. The player must keep track of their ammo: This is Amagon's only means of attack and should his ammunition run out he will be unable to attack enemies.
Amagon can upgrade his strength after collecting enough points - either from defeating enemies or collecting items - and a special Megagon Key power-up. Hitting Select when these conditions are met turns him into Megagon, a considerably more powerful alter ego. Megagon can take several hits and has a powerful wave beam attack that also drops his health. When Megagon runs out of health he simply reverts back to Amagon's weaker form.