Tetreous Alter is one of the two planets that the Triobots inhabit. Not much else is known about it except that it is slightly smaller than Tetreous Prime, but the two planets are otherwise nearly identical.
Selecting this planet in Super Mega Extreme Cyber Ortek Flier 2005 X displays a message saying that it doesn't exist yet but might be playable in a later version of the game. This has not happened as Pseudolonewolf has stated that he doesn't plan to do anything else with SMECOF2005X since he has other games he needs to work on. He also said that he is satisfied with the game as it is. This planet, along with Anthope α and Anthope β, are currently inaccessible in the game.