Just like battlefield 2 for the 360, Chromehounds has a pretty dull singleplayer, but awesome multiplayer!
Singleplayer: Basically training for multiplayer. Simple easy levels that get you parts that you can use for multiplayer. There are about 7 levels for eatch RT (role type) and those include Soldier, Sniper, Scout, Defender, Heavy Gunner, and Commander. Nothing special there.
Multiplayer: The multiplayer is where it is at for this game! You can participate in matches like deathmatch or team deathmatch you can capture combas' which is like capter the flag, but with multiple things to capture. Pretty much anything like that. To participate in the war is the funnest part though. The only downside is you NEED to join a squad to participate in the war and new people don't get accepted very easily sometimes. Customization is AWESOME you can spend literally hours if not more trying out different setups.
Basically if you want the japan flying mechs with super swords and jetpacks with super fantasy action this game is not for you. This is basically a simulator of how mechs would work if they were real. Lots and lots of tactics.