This game is fantastic for players like me who have always found easier routes to a particular destination but could never use them. It sort of plays like a better Bioshock, but not quite and certainly lacks the same atmosphere. To be fair though I doubt any game could come close to replicating the latter. Currently I have a couple of huge issues with it at the moment: Lack of non-lethal hand to hand options in combat, scarcity of non-lethal item drops, and the god damn gray colored microsized text on standard definition sets. If I have to constantly backtrack to HQ for shop access then that's another strike against it.
The lot of which are slowly starting to irritate the f*ck out of me, but not enough to stop playing entirely. The severe lack of non-lethal combat options however is coming pretty damn close. It just flat out doesn't make any sense providing a playstyle attached to achievements and the ending, but only lending support for a defensive approach. Much more nonsensical for a game praised for allowing players near endless freedom of approach.
I don't know about the rest of you but I'd rather permanently kill or knock a guard the hell out than sneak past and have to deal with him on the way out. Currently the non-lethal player has three options - Choke/Dart, Distract, Never Get Caught/Run Away And Hide Until You Get Another Opportunity To Choke/Dart.
It's completely f*cking ridiculous for any assassin to be locked out of bare Hand to Hand combat in any situation. Everything else besides this point though is more or less golden so I'm glad I bought it.