A worthy follow up to the original C&C. In the C&C universe World War II didn't happen in quite the same way as we are told. After the war Albert Einstein uses a time machine to go back and assassinate the young Adolf Hitler, which subsequently prevents Nazi Germany from ever coming to power. Thus WWII is averted and the world proceeds into the 1950s in relative peace. As a result of the war not being there to cut down a whole generation of the best and brightest minds highly advanced technology is developed decades ahead of schedule, thus explaining why are there things such as GPS satellites in this time period. However without the Nazis to act as a counterweight the Soviet Union grows immensely powerful and begins to get territory ambitions of it's own. Thus WWII breaks out anyway with the Allied nations against the Soviet Union under Joseph Stalin (as well as an appearance by baddest dude in the history of video games, Kane.)
I score this one a little lower than the original as the game doesn't really do anything the first one didn't and changes a few things that were best left alone. Many of the units are recycled from the original game (as in allied light tanks, medium tanks, Soviet Mammoths, as well as nearly all the trooper graphics.) However there are lots of new units, such as Mig's, Yak fighters, medics, etc. Also this was the first game to feature a one of a kind "hero" unit that could only be built once (Tanya.) The two sides are a little unbalanced as the allies don't have an effective super weapon (the chronosphere could only transport one unit at a time) while the soviets have two, the Iron curtain and a one time Nuke (which was drastically weakened.) Soviets also have a major advantage when it comes to armor (as the allies are restricted to light and medium tanks, which need to be in force to be effective,) however they suffer from not having a comparable Tanya/commando unit. This game also introduced naval units to C&C. Soviets can only make subs, while Allies have a Cruiser unit that can lob shells from two screens away, however if the map has no water this advantage is neutralized.
Engineers have also been weakened significantly, as you can only capture a structure that is on the verge of exploding which effectively prevents engineer rushes as a viable strategy. Allies have very poor base defense, with the NOD turret and a machine gun bunker (neither or which are very effective,) while soviets get flame towers and Tesla coils, both of which are highly effective against troops and armor alike. This game also introduced a "radar jammer," which allowed you to block your enemy's view of your base and a GPS satellite to reveal the whole map, both of which would later appear in RA2. Perhaps the biggest innovations to the series involve various acts of subterfuge with spy and thief units that can do things like steal money and cut power to a base, however both are pretty useless beyond that (the spy would be significantly strengthened in the sequel to this game. ) This game is also the only in the series that includes indoor missions, which are kind of a mixed bag. They're interesting and challenging but mainly involve you moving engineers to certain places through a maze.
The game is still pretty involving, and the on-disc missions are fun. You can still very occasionally play this on-line via Gamespy once in a while. The addition of attack dogs, spies, thieves, flame towers, etc. mix up the formula from the first C&C. I definitely recommend picking this one up to anyone out there who is a fan of the series.