I played through halo wars on the "normal" difficulty and thought it was a little too short. I really liked it- I had just wished it was longer. I decided I couldn't recommend people spend more than $20, but if they could find it for cheaper to jump on it. At any rate, I started playing it on "Legendary" for the achievement and it's really kicking my trash. It's forced me to dig much deeper and be much more strategic. I'm about half way through and I've been winning by the skin of my teeth. I've decided this is the way to play it- play through once semi-quickly to learn it & enjoy the story. Play through again on the harder difficulty to get a real challenge. And, like StarCraft, you should theoretically play 50x as much online as you do the campaign.

There were a couple times in my first playthrough that I found myself fighting the controls instead of the Covenant... but I think I'm totally past that now.

I'm also sort of playing Star Wars: Empire At War on my laptop. I find that game to be harder to control with a mouse and keyboard than I find Halo Wars.