At least the PC version is. I’ve been trying to complete all the games I own which includes the Splinter Cell series and the one game I hadn’t finished yet was Double Agent. I took advantage of the Steam Summer Sales and decided to buy it, since it was so cheap. Even at this price I regret paying for it. It is one of the buggiest games I have ever played and if you really want to play it, I’d suggest getting it on a console. With that being said I have no idea if the bugs are on the console versions as well, but on the PC version, every mission had some bug that prevented me from completing my objectives or certain animations/actions and sequences just didn’t work correctly. There were times I had to reload saves and sometimes even restart the whole mission. Luckily the game isn’t that long but it really was one of the most frustrating gaming experiences I’ve ever had.
If the PC is the only option you have for playing this game, then forget it. If you’re still considering it then stop, seriously it’s not worth it, especially now that it’s no longer on sale. The game itself isn’t that great either, and this is coming from a Splinter Cell fan. Now that I’ve played all of them, I don’t know which is best, but Double Agent is certainly the worst!