Assassin's Creed will feature additional investigation side-missions when it launches on PC at the end of next month.
Ubisoft also says that Assassin's Creed has sold more than 5 million units on PlayStation 3 and Xbox 360 since its launch in mid-November.
Due out 28th March, Assassin's Creed: Director's Cut Edition will add four new types of investigation, although Ubisoft has yet to say what they will be.
In PS3 and 360 versions, investigations were used to build up intelligence about an assassination target and included things like pickpocketing, taking out guards on behalf of an informant, and eavesdropping on conversations.
They were unlocked by climbing to the top of a nearby tower and "synchronising" Altair with his surroundings.
Reviewers, us included, complained that they became repetitive and that some were rather simple, but the silent assassinations were pretty hardcore, and we liked the ones that involved jumping around collecting flags. Four new types will hopefully improve the sense of variety.
Assassin's Creed itself, if you've been hiding in a haystack, is an openworld game set during the Third Crusade where disgraced assassin Altair has to rebuild his reputation by killing the corrupt men his master Al-Mualim sends him after.
As the game progresses and Altair becomes more enlightened and inquisitive, he learns a lot about himself and others around him. It's basically Casper Meets Wendy but with monks and pillaging.
The game was also hugely anticipated because of its slightly baffling science-fiction bits, which will aim to tie a broader story together across two further instalments.
Check out our Assassin's Creed review for more on what we made of Ubisoft Montreal's opus, and watch out for a PC review towards the end of March.