Save your money. It's an awful game and has so little in common with the previous entries to the series. Everything you love was taken out of the Absolution and it got replaced with linear levels, a rechargable magic bar, a fucking score that updates while you play (so if you want to get SA rating you will be restarting dozens of times). It's closer to Splinter Cell than Hitman in that you have a series of linear areas and you stealth between them, occasionally changing a costume or taking someone out.
It sucks as a straight up action game, it sucks as a stealth game, it sucks as a Hitman game, it sucks as a puzzle game. About the *only* thing remotely close to actual Hitman gameplay is, funnily enough, the multiplayer mode. In MP, players pick a map, distribute some targets about it and set a time or method of killing (or other criteria). The player then tries to beat the challenge.
Gone are the open maps, gone are multiple routes, costumes, weapons and the rest. Replaced with a dull game that I got bored of a few chapters in (the convent), uninstalled and never thought about since. Seriously, save your money and play Blood Money again for a great experience. Or, install Contracts which is now on Steam (evidently that years-long copyright issue has been resolved) and play the Hotel level, remade from the original game (but with Hitman 3's better graphics, saving ability, weapons, etc). The Hotel level in Contracts is an absolute masterpiece of game design, Hitman, and gaming at its finest. Alongside Oblivion's "Whodunit?" mission for the DB, Hitman's Hotel level is one of the best missions of any game, ever.
The new magic mechanic, focus or whateverTF it's called, is bollocks. You also have infinite knock-outs, unlike older games where you only get two non-lethal takedowns per mission). I even tried a cheat with infinite focus to see if it helped make the game any better (by removing focus from the equation)...it didn't.
TL

R - Save your money and play Blood Money or Contracts again instead. Either are significantly better than Absolution.