You would never think of Halo and real-time strategy, the two might not mix all that well. Halo Wars was a huge deal when it was first released as it was a huge risk. It was the first time anyone but Bungie touched the Halo franchise and many were skeptical. To my own surprise, the game checks off most of a good RTS game off the list, but being the first time into this category it does have its issues.
The first issue being the story. The 15 missions are accompanied by pretty pre-rendered cutscenes we have grown to love from the series with great voice acting and stellar music. You play as Sgt. Forge who is assigned to the Spirit of Fire and must destroy an ancient world that is full of an unstoppable army built by an ancient race. The Covenant want these weapons and they capture a human scientist named Anders as the machines can only be activated by human touch. It's not the best story and it really fills a minute gap in the Halo timeline and doesn't really mean all that much.
When it comes to actually playing the game you are greeted with RTS basics, and I mean the minimum basics as the game never moves on past that. Most RTS games require you to find and acquire resources to build an army to defeat the enemy. Halo Wars has only one resource and this is in the form of the generic supplies. You can find crates along the ground, but you must build supply pads on your base and this is the first thing you do every single mission. Second, your base has limited slots for buildings, and this is where the game breaks down a little. I would have 3-4 supply pads upgraded to advanced ones and it still takes forever to get enough resources to steadily upgrade all my buildings and troops. A solid 25-30 minutes is needed just to maintain an army to defeat most enemies on a map and even longer to get all the upgrades.
It's a frustrating battle of nursing your resources with most time spent waiting for them to accumulate which is not fun and quite boring. Nearly every mission where I was given a base had my guys just standing there for 20 minutes so I could research as much as possible for only what I needed for that map. The Armory is used to research tech only and this comes in the form of +10 to population, Spirit of Fire strikes, more troops per unit etc. After you acquire all research here which is only a couple of tiers the building is useless and you can recycle it and build another supply pad. The Barracks is used for only two ground troops and researching their upgrades. The Air Depot has three different air types and the Vehicle Depot has a few things as well. It's very basic with only core Halo units you have seen in the console games. It covers every discipline well and they all do their job fine, but some units require over a thousand supplies and this can take up to 1-2 minutes to accumulate just for one unit. So instead of being able to send out drones to acquire a mass amount of supplies, everything is rigged to a timer essentially and it makes things not very fun.
The population cap is 40 and that's not many troops considering some larger units can take up to 6 population slots. Once you get them out and fighting it looks pretty awesome and feels just like a Halo game with familiar enemies and sounds. The Spirit of Fire attacks can give you a leg up, but it doesn't feel as powerful as it should. A MAC attack or carpet bomb, even fully upgraded, may do 1/8 to 1/4 damage on an enemy base. You would expect for the long cooldown time that you can wipe out all of or most of a base and larger enemy units. It's so incredibly unbalanced and frustrating that I always felt I never had an advantage no matter how well I played. Even when you get multiple bases it doesn't help outside of giving you quicker access to troops and more supply pads. With the pop cap at 40 you would think more bases would mean a larger population increase.
Missions are at least varied with some escorts, defense, offense, and various others. One frustrating mission had me on a ship fending off Flood with a timed sweep that killed everything in sight. It took almost 45 minutes just to clear everything off the ship. Another mission had me station vehicles at 5 different spots to blow open a large base shield. I had to constantly go back and forth defending them and clearing spots to put them down. There are not enough troops to leave with each vehicle due to the low population cap. Every troop is essential.
With all that said, Halo Wars has the units, looks, and sound down for a great RTS game, but it's so rudimentary, unbalanced, and boring with a majority of your time waiting for things to build and cooldown. There's a lot of mission variety, but it won't matter as the rest of the game plagues these missions. The story is also nothing memorable and doesn't mean much in the Halo universe. I really can't recommend this to RTS fans or Halo fans unless you're curious.