The peaceful Sulabacca island of the slime kingdom of Sulan has been invaded! All 100 of the inhabitants of the island have been kidnapped by the Shippo Dan. You alone remain to save all of the villagers from their grisly fate.

Slime MoriMori 2 has you trekking through various dungeons in search of kidnapped slimes. Your slime can hop around, float across chasms and attack using its own body as a weapon. By stretching itself and then releasing, the slime flings itself around like a rubber band, attacking enemies and ricocheting off walls. This same move is used to strike items and rescuable friends. Either the item or friend is launched into the air, so you can catch them and carry them to a safe location. The dungeons are very reminiscent of those you might see in a classically-styled 2D Legend of Zelda game filled with a variety of enemies and focusing on puzzle-solving to get through them.

In addition to this, at certain times, you must defend yourself from attack by using your Slime Tank. Battles here consist of loading your tank with ammunition that falls from chutes, and firing the ammunition to attack your opponent, or to block your opponent's fire.