Mujintou Monogatari 4 is a "survival life simulation" game and is essentially a retelling of the first game. A plane crashes into the sea, but a child survives and wakes up on a seemingly deserted island. The child finds another survivor and a cabin with a few basic supplies. After watching the lengthy intro, the player is given both heroes to manage. Water, food, light sources and materials have to be gathered and new tools can be crafted, provided the characters have all the necessary materials and knowledge.

Compared to the original game, Mujintou Monogatari 4 changes the gameplay to make it more of an Action RPG, with players having to control the characters using a mouse and double-clicking on an item or enemy to gather or attack it. Players can find other survivors and have control of 3 unique pairs of characters which can explore various areas of the island. Each character's statistics can change depending on the activities that players make them do.

A plane crashes into the sea, but the protagonist survives and reaches a seemingly deserted island. He teams up with other survivors and explores the island.