Skull Slayer is a single-player fighting game against an automated opponent. The game features 3 modes, easy difficulty mode, normal difficulty mode, and expert difficulty mode. The player takes turns attacking and defending. The aim is to defeat the boss. While attacking, the player must choose the strength of the attack which will present the player with a series of keys that must be pressed in order to do a successful attack. While defending, the player must simply dodge fireballs. The amount and speed of fireballs vary with the strength of attack that the player performed.