Alternate history asks the question "what if?": what if the other side had won World War II, if the atomic age had unfolded differently, and the Roman Empire had not fallen? Games in this genre rewrite real events and build their own world based on them. This is the structure of Fallout, Wolfenstein, BioShock, and many strategy games.
Often yes, if unprecedented technologies have appeared in the changed world. But there are also almost realistic alternatives. Similar labels are "Historical" and "Steampunk . "
All alternate history games on the site are available for torrent download — sort the list by rating, size, or year of release.