Mujintō Monogatari 3: A.D.1999 Tokyo is similar in concept to the two previous entries in the series, being a "survival life" simulation game. However, its setting is quite different: rather than getting stranded on a deserted tropical island, the protagonist travels in subway when a terrible earthquake occurs. Climbing out of the underground tunnels, the hero discovers, to his horror, that Tokyo has been nearly destroyed and deserted. Teaming up with other survivors, the protagonist has to explore the ruins and stay alive.

The basic gameplay is similar to that of the two predecessors: the player manages parties of survivors, assigning activities to them (exploring, resting, finding items, etc.), then completing the day and watching these events unfold automatically. Water, food, light, and various materials can be found and collected. It is also possible to craft own items. Scripted events introduce new characters to the team. Hostile encounters may also occur; the player can either choose to fight, retreat, or deal with the potential enemies. There is no active control of the characters during battles.

[From MobyGames]