Dungeon of the Endless is a tower defense game and the third in the series which includes Endless Space and Endless Legend. The game plot is about a prison spaceship which escape pod had crashed in the alien planet. The player controls survivors from that ship, who have to escape the multi-layered structure in the strange planet by taking an energy crystal through several floors filled with angry creatures. There are randomly generated levels in the game in which the player has not only to explore but also to collect resources in order to enable power to various rooms and turrets to divert attention of enemies in order to move the crystal from the starting point of the level into the elevator to the next floor.
In each level of the game the player has to choose two characters who are different in their stats such as health, attack, defense power and movement speed. The player has the option to either control one of two selected characters separately or in tandem.