Twenty bucks for six missions. That comes out to $3.33 a mission. Not worth purchasing.
The issue with the game is that it offers little to no new content in the big categories: Game play, Single Player, and Mutilplayer.
The game play remains identical to the original. There are no new units, no new game modes, no new special abilities, and no new tactical aid. As before, each of the three sides (US, NATO, and USSR) have the exact same units, which vary only in appearance, and occasionally, special ability.
The additional single player content takes the form of 6 new missions from the Soviet perspective, but they are interweaved with the original US campaign. They offer very little in the way of different kinds of missions from the original campaign too, and the only thing that staves off a constant sense of "Haven't I already done this?" is the fact that the voice-overs are done in Russian accents.
Finally, we see no new content in the multiplayer category, as the two new maps that comes with the expansion were already available for free download. Heck, they weren't even made by the game designers, but by fans.
So, despite its potential, for failing to build on an already stellar game, and delivering a disappointing amount of new content, World in Conflict: Soviet Assault, receives a 3.5 out of 10.