It's not the worst game, but definitely not worth buying.
All is not lost, the game is in a way fun to run through like an impossible soldier that can take many bullets. I have to admit it is kind of fun to use a sniper on the run.
The harder difficulties are much more annoying than being on easy where you can take 30 bullets and not die. The only thing about this game that's interesting is the sniping "kill cam" type shots where you can view internal organs being demolished by a bullet. That however gets old very fast, and once you've alerted the place, the ones you want to see never get shown.
Also, you're easily seen. You can be seen in the shadows, behind cover, even the slightest peek the AI will spot you. They seem to be amazing eagle eyes yet they can't seem to come after you properly. They run around like puppies and take cover behind something around a corner for no reason... then come running out and take cover behind something that seems reasonable. They know you're there, everyone knows where you are as soon as you're spotted. I'm not sure how they know, but they do. You get to run away, and you leave behind a ghost shamefully ripped off from Splinter Cell Conviction. But doesn't work nearly as good, because if at any point you were lucky enough to draw the enemy towards you, they spot you immediately behind cover in the shadows. You could be buried in the dirt, wearing bushes, but you'll never stay hidden.
It isn't impossible to get through a mission unseen, but it's also not really worth it with the unreliable mechanics, most likely you'll be seen after you spent hours and hours trying to sneak by. Then you're surrounded and the game just becomes a very weak and lame shooter. There is nothing good about that at all. In a game where you'd love to be able to sneak around sniping people, you're barely able to move without being detected. Definitely a shame, it had potential.
There are some nice features, such as booby trapping with trip wires and landmines, and you can throw rocks to distract people... but most of the time that's worthless because of how stupid the AI is, they'll never give chase or come into a building you're in. So that feature is almost worthless. Sadly...
The more you play, the worse the game gets. In larger maps the AI is highly annoying. You snipe someone, they see you despite your best efforts, you hide, they find you, you wind up killing everything with 1 of 3 guns. The more levels you get through, the more boring it gets. It's also extremely short.
Not important, but the graphics aren't that great. It reminds me of Max Payne 2 which came out years ago. Only, the game doesn't play nearly as well. There are entirely too many games out there better than this, and if a developer wants to compete in this age they need to be original and on top of that they need to make the mechanics they put in work properly, and make the gameplay worthy of having anything to do with a sniper, if they're going to call it Sniper Elite. This game comes down to nothing but weak shooter type gaming... and it plays badly, looks poor, sounds poor, and tells a boring story that nobody is paying much attention to anyway.
I didn't bother trying the co-op or multiplayer modes, because I wouldn't dare ask anyone else to purchase this game. In fact I would recommend not buying it, not renting it, and not wasting your time with unfinished games. It's half done by any level headed and experienced gamer. If you haven't played Splinter Cell Conviction, then buy that instead. It's a million times better than this game.