Resequence
From Achron Wiki
The Resequence engine is the game engine that Achron runs on and is what makes Time travel possible. The resequence engine uses time waves to handle changes to the past and Paradoxes. The RTS functionality of Achron is highly separated from the Resequence engine making it easier to use Resequence in other games such as puzzle games. It does not require 1.21 Gigawatts of power to operate.