Big fan, tried every game of the series I think (loved the movie too, and even went to a Halloween party as #47), but I haven't finished a single one of 'm. I love the concept, but somehow the genre simply isn't my thing. I want to play the game as a proper hitman (as opposed to a running arsenal) but I get stuck and when I then read a walkthrough on how it should be done it simply is too far-out for me. You follow your idea on how it should be done, play out a good part of the level and when you reach the actual kill it doesn't work because you forgot something, or because other far-fetched steps are required.
I guess I just don't 'read' game mechanics very well. I had the same thing years ago with stuff like Indy: Fate Of Atlantis. You know sort of what's expected of you, but when you read what you have to do to solve a certain puzzle I'm always like 'Wtf? Really? I need to combine this sextant with a banana?"
So yeah, I love Hitman, but hate it as well, cuz apparently I can't enjoy it as it's meant to be. I do remember the first one being buggy as hell. Sometimes you fucked up royally but still could make it out of town alive by hiding and kill everyone that came around the corner, eventually they would stop coming and you could walk away.
