One unique feature of the Supreme Ruler Game Engine is that we don't put any type of caps on the number of units a nation can have. So as games go on, every country tends to continue to grow their military significantly. This can mean literally thousands of units constantly active (not just in player countries but also in AI nations) that the engine must continually monitor and often control.
In previous versions of the game this could sometimes lead to significant slow downs as the games progressed to later stages and unit counts got high.
Much work has been done to improve this in Supreme Ruler 1936, and the improvements are Dramatic! In recent single player test games, after 12 years in and wars going on around the world, at fastest speed we are still achieving under 5 seconds per game day speed (too fast if you are trying to control the course of a battle). So unlike our previous releases, in later stages of this game you will often need to move to a slower game speed.