The expansion adds a new Aztec pantheon and significantly reworks familiar mechanics.
The main feature of the DLC is the ability to play as the Aztecs. Three major gods have been added to the game, including Tezcatlipoca, along with nine minor ones.
Battles have become darker thanks to Tonalli energy. This resource is obtained from defeated enemies or from sacrificing villagers and is used to summon divine powers. The gameplay emphasizes fear, illusions on the battlefield, and the construction of towers made from enemies' bodies.
In addition to multiplayer, Obsidian Mirror includes a story campaign: 12 missions about the conflict between two divine brothers for power over the world. The free update also introduced a number of improvements.
Owners of the Blood and Bones pack received more combat-focused animations, while the Ultimate edition now includes golden statues of the new gods.