Halo Wars is a great RTS, but compare this to the rest of the series, it's doomed.
The controls take some time to get use to, basically, if you played an RTS before, you probably been through that. The Combat is like a "rock-paper-scissors" system. In general, ground vehicles are effective in combat against infantry, infantry are effective against aircraft, and aircraft are effective against vehicles.
Sometimes it can get a bit frustrating, mostly because of it's high over-head view, it's like 25 feet up-word, it can get difficult, mostly because of how much people can be on the screen at once, it is one of the most frustrating problems in the Game.
As Far as i know, this takes place before Combat Evolved a.k.a Halo 1, and The Spirit of Fire is sent to the ruined planet Harvest to investigate Covenant activity, where Cutter learns that the Covenant has excavated something at the planet's northern pole.When the UNSC's main outpost on Harvest is captured, Cutter orders Forge to retake it.Soon after, Forge scouts the Covenant excavation and discovers that they, under the direction of the Arbiter, have discovered a Forerunner facility. Forge's troops defeat the Covenant forces before they can destroy the installation, and Anders arrives. She determines that the facility is an interstellar map, and recognizes a set of coordinates that points to the human colony of Arcadia.
In my opinion, Halo Wars wasn't BAD, but it's not a great as it's predecessors, AND if this wasn't Halo, there probably be no interest to the game, but is it worth the $60? (WTF?) Heck, no, wait a while for the prices go down, say like $40. That said, i recommend it, but not at a Extremely High price.