It is suggested you do the campaigns in the order they are presented, from left to right (i.e., Soviets, Allies, Rising Sun). The difficulty level of each campaign increases from Soviet, to Allied, to Rising Sun.
The Rising Sun missions are some of the hardest in the game, and will be a challenge to veteran RTS (real time strategy) commanders. You should build your knowledge of game strategies, units, and tactics by doing the easier campaigns before tackling Rising Sun.
Also, the live action storyline and the background information it provides will make more sense if you do them from left to right.
Whether or not you've played a Command and Conquer game before, you should still go through the tutorials provided. The tutorials have step by step instructions showing how the units of each faction are built, how they operate, and how they are different from the other factions. Just playing previous C&C titles will only give you a feel for controlling the battlefield; it won't give you insight into the capabilities of your armies.
While watching the tutorials, make a point to view the brief focus videos available for certain highlighted units. They will show the base operations and special abilities of those units.
You may find it helpful to go through the tutorials again after you finish the campaign for one faction, and before you start playing the next faction. Then you can focus on the units and structures for the faction you are about to play.
The co-commander feature of the game is either the best or the worst part of it depending on who you talk to. The positive aspects of this feature include the following:
- Each mission of each campaign is already set up for co-op play with another real live person, who just takes the place of your AI co-commander
- Your AI co-commander will carry out some of the mission requirements without your involvement, leaving you free to accomplish other requirements, or freelance
- Your AI co-commander is aware if you get overwhelmed, and will frequently save the day (i.e., your base) without you even asking for help!
- Your AI co-commander, in some missions, will have superweapons that you can dictate the use of (usually by selecting an enemy structure and using the menu option for your co-commander to attack it)
- Your AI co-commander can be ordered to strike a target, or move units to a position, with some restrictions (given below)
- Your AI co-commander will usually call for help when they need it (which is rarely)
On the other hand, your AI co-commander can be frustrating when they:
- Tell you that they will accomplish a certain tactic or mission requirement, and then fail to accomplish it
- Are ordered by you to take position, strike a target, etc. and they fail to do it
- Get overwhelmed by the enemy AI and are wiped out, sometimes without telling you
My experience so far is that your AI co-commander operates with competence and intelligence for the most part. Just like a human player, when they say they are going to accomplish something, their ability to do it always hinges upon their being able to overcome the enemy defenses, or the enemy attacking them. Sometimes the bad guys get the best of them, just like you. If you decide you want your co-commander to attack a certain enemy target, you need to realize that they may not have the units to spare, or that they may be engaged in a battle that is occupying their entire force. So, as long as you don't treat the co-commander hotkey commands like a superweapon at your beck-and-call, you should make it through the campaigns successfully.
A successful co-op strategy to use with your AI co-commander is to leave their forces under their full command, pay attention to their messages to you which may signal change of strategy, and use direct commands such as strike a target or take a position sparingly.
The exception to this is the small commando missions where your co-commander is managing a Natasha or Tanya unit, in which case you will need to be very active in selecting targets and taking positions.