Original sentence: There were 500 versions of the final cutscene, but due to recent upgrades, there are now over 10,000 different versions, which was determined by all of the actions taken by the player
Edited sentence: There were 500 versions of the final cutscene, but due to recent upgrades, there are now over 10,000 different versions (permutations), which was determined by all of the actions taken by the player.This isn't really that much, Fallout 1 has 360 possible permutations (with 19 different endings) and  Fallout 2 has 47 endings with 1,105,920 permutations