If you're a veteran of RTS games and a fan or Ensemble's older games, don't buy Halo Wars. If you're new to the RTS genre, by all means, play it. It's a great introduction to RTS games.
For those who are used to RTS games, you'll be a little disappointed with many aspects of the game. Your choices for building a base a very limited. Initially, you can build on three predetermined spots around your base. You can upgrade the base once to gain two more building spots and the option to build up to four turrets. Upgrading again gives you another two building locations, for a total of seven. That's all you get until you build another base, which you can only do in a few predetermined spots.
The game's controls for selecting units are clumsy at times. You can press the left bumper to select all of your units, or right bumper to select all of them that are currently on the screen. You can also press A when you're on a unit to select it, or hold in A to make a larger circle appear and "paint" a group. Two major things are missing from this control scheme. First, once you have a group selected, if you want to remove just one unit from that group, you can't. You'll have to move that unit individually somewhere else so you don't accidentally select it again, then reselect the entire group. Second, once you've selected a group, you can't add new units to it. For instance, if you want two groups from opposite sides of the map to converge on a target, you'll have to use that brush feature to select them all at once. You can't select one group, then add the other.
The tech tree for this game is also very broad and shallow compared to other RTS games. You can build almost all of the buildings or units you'll ever be able to build immediately. You can upgrade most of the units and leader powers three times, or four in a few cases. You'll never really research new units. You'll only upgrade the original ones.
Resource management is very basic. You can build supply pads or warehouses (depending whether you've chosen a Covenant leader or a UNSC leader) which will bring in a steady stream of supplies. There are also a few crates laying around that your infantry units can use to collect more. There is only one type of resource to manage.
You also have a population cap of thirty, which can be upgraded to forty with some research. Different units use up different amounts of that limit, from one for basic infantry on up to twenty for the Covenant's scarab. Your technology level is also important; it determines what technology you can research. You can increase it by building and upgrading reactors for the UNSC or by building and upgrading your temple for the Covenant. There are also certain structures spread around the map that can be taken over to increase the tech level.
All of these things may disappoint the veteran RTS gamer, but will be nice for those who are new to the genre. There is less to think about than in other RTS games, so it's less overwhelming. Also, these features facilitate faster matches, which is nice for a matchmaking environment.
The single player campaign is excellent, including the story line and the graphics. The cut scenes are some of the best you'll see in an XBox 360 game. The stunning visuals, captivating storyline, intense dialogs, and adrenaline-fueled soundtrack do a lot of good for the game too. Halo fans will be very interested in seeing this part of the story. The skulls spread throughout the campaign can be used to make the game easier, harder, or just more entertaining.
Skirmish mode gives you an opportunity to play in a multiplayer-like environment without having XBox Live. The AI players can be set to be ridiculously easy, or remarkably difficult. You can play one on one, two on two, or three on three, and you can mix and match AI and human teammates and opponents.
Halo Wars is far from the best RTS option available, but if you're looking for an introduction to RTS games or want a break from the difficulty of other ones, it's just fine.
And Ensemble, we're all going to miss you.