With the new Hitman game launching in a couple of weeks, I think it would be good to discuss tags for it ahead of time. This is complicated by the fact that they've decided to call it "Hitman 2", despite that being a game from 2002 - "Hitman 2: Silent Assassin".
With no subtitle, I think the best tag for this new game would be hitman-2, or hitman-2-2018 to be less ambiguous.
There is currently a tag for the original Hitman 2 with 2 questions: hitman-2. This could be changed to hitman-2-silent-assassin or hitman-2-2002.
The plain hitman tag is used for the 2016 game which was ostensibly just called "Hitman", although it was also marketed as "Hitman: The Complete First Season". As they decided against continuing the "series" nomenclature, it would probably be better to move these questions to hitman-2016. There's also one question tagged hitman-beta which is just odd.
If the 2016 questions were moved to hitman-2016 then I'd suggest making hitman a synonym for hitman-series.