World in Conflict and its expansion Soviet Assault are both real time strategy games set in alternate history where World War 3 erupted due to a Soviet invasion of the USA. The premise might be a bit cheesy at this point, but the gameplay was and still is extremely solid, with a special mention going out to the campaign that manages to remain consistently engaging.
If this sounds like the type of game you would want to try out, you're in luck as Ubisoft is currently giving away World in Conflict: Complete Edition for free! Simply head over to the Ubisoft website, create a Uplay account if you don't own one, and that's pretty much it as far as claiming your key is concerned. What you should keep in mind, however, is that this offer will only last until 11am UTC on December 11th!
For those of you wondering whether World in Conflict is even worth the time and effort it takes to install it, I would say the answer is a definite yes. I have no idea whether the multiplayer scene is active these days, but the singleplayer campaign alone is good enough to warrant at least one playthrough. It has some interesting characters and story ideas, there is a decent amount of challenge in just about every mission, and most impressively of all, you can obliterate just about everything in sight. So if you're even remotely interested in RTS games, I would say World in Conflict is well worth playing, especially when you can get it for free!
As a final note, allow me to send you off with a trailer for the Soviet Assault expansion. It doesn't feature any 'real' gameplay, but it should give you a good idea of the themes and tones World in Conflict is going for. Enjoy!