A side-scrolling platformer developed and published by SunSoft for the Famicom Disk System. It is the third entry in a series of educational math games.

Chitei Tairiku Orudora ("Underground Continent Orudora") is a Famicom Disk System action platformer from SunSoft and the third part of their Chinou Game Series, each borrowing an existing NES game's model (in Orudora's case, Atlantis no Nazo) and adding arithmetic problems to it. In Orudora, the actual math puzzles are relegated to an ancillary mini-game found on the disk.

The goal of the game is to help a young explorer pass through the underground world of Orudora, taking out enemies along the way with his bombs. The bombs fly in a specific arc, so the player needs to be the right distance from the enemy in order to hit it. The player character can also crouch, jump, climb ladders and use other abilities common to platformers.

The two other Chinou Game Series games are Adian no Tsue and Super Boy Allan, the latter of which was released on the same day as Chisoko Tairiku Orudora.