Except for the larger rogue v rogue combat scene it reminded me greatly of the playstyle of a now-graphic-obsolete but awesome game series Thief (The dark project/The Metal Age/Deadly Shadows). Whole game you sneak around mansions/castles/cities, pickpocket/backstab/snipe guards, hide bodies, jump between rooftops/rafters, and occasional hand-to-hand with guards or undead. Usually ranked top 50 games of all time, and was the predecessor/base of other stealth games like Assassin's Creed and Splinter Cell. The video has the same feel to it and especially the first half nearly identical playstyle.
/end shameless promotion
Either way yea that's a sweet video and he has plans of releasing more or possibly making it a series. Link em when you find em.