Hindered by strange bugs and sloppy camera control, this game is overhyped at best.
Double Agent stumbled right out of the gate, however. I started the game, and the first mission had no intro, no practical training, no hints given about how the mission connected to the rest of the game, etc. That's not how Splinter Cell works; you pull the audience in and THEN let them play. You don't just start a game with a mission and casually say, "Hey Fisher, it's Lambert, Investigate this thing like you always do. Bye."
Another thing that gets on my nerves: most of the storyline is explained over the loading screen. Quick, short bursts of dialogue that vaguely touch upon the story. Sam goes through quite the crisis in this game, and it gets maybe a few sentences dedicated to it before being abandoned altogether. Cut scenes aren't really existent, except to show Sam standing in a plane, or a guard standing in a tower.
What else? Gunshots and random sounds from cutscenes are incredibly loud, causing me to jump up and adjust my speakers everytime something happens in the game. Camera controls aren't nearly as tight as in previous games; I've hidden behind boxes only to find myself staring at the side of Sam's head. I know this game is supposed to deviate away from the pure stealth genre, but is it really necessary for Sam to go through a mission completely detectable....especially since it's the mission after he gets back his nightvision goggles?
Bugs: I'll escape to the main menu to quit to Windows....main menu pops up....a random quick save starts loading and takes 30 seconds before it lets me access a menu again. Moving the camera around results in different noise, which Ubisoft says is the fault of Windows not detecting speaker systems appropriately....without examining the issue too in-depth, I'd say that is a lie. Increasing the graphics on this game when your system can't handle it will result in a string of undecipherable errors. Did you screw up a mission and go back to the main menu to start over? Have fun with the unskippable menu cutscene (sometimes pressing "escape" brings the menu up quicker), the loading screen, the SECOND loading screen, and then another unskippable cutscene of Sam standing on a plane.
Bottom line: if you're running a system capable of running this game at full graphics and you happen to see a used copy somewhere for $5, pick it up and play around with it. However, you shouldn't expect very much from the game.