Command & Conquer: Red Alert 2 [RIP]

Every aspect of gameplay in the game is based on the collection of money. In the game, money can be collected by several means. The most common is using Miner trucks to gather Ore and/or Gems and transport them to a Refinery. A player can also gain a lasting income by capturing Oil derricks (neutral buildings that are present in some maps). There also are two one-time sources of money for Allied and Soviet players, namely collecting random crates which are present in the map and selling off buildings which are controlled by the player. Allied players have a third one-time sources of money using a spy to steal an enemy's money. The money is spent on constructing and repairing buildings and units. In both cases one can start construction before having the full cost in one's reserves, as construction pauses if one runs short of money.
The various nations are members of either the Soviet or the Allied factions. One of the major praises of Red Alert 2 over the original Red Alert game was that playing as a specific country now actually made a difference. While every country has the basic buildings and units, each nation has a special unique unit, or a unique ability or structure. This changed up the popular skirmish games, allowing for new strategies.
It is also the first C&C RTS not to include a mission select screen prior to levels that change the conditions of the next level.