I am a HUGE fan of halo war along with all of the halo franchise. In my opinion halo wars needs a few key things
1. The ability to place bases wherever you choose on the map
2. More options for strategy I.e the ability to place heavy turrets anywhere (maybe ever fire them down from ship like spirit of fire)
3. And lastly unlimited or very large troop limit, hard to feel like your commanding an army with only 30 population limit and tanks and such take more than one population
this being said I love the original still play it to this day and would be so excited if it got a sequel I might even buy multiple copies (by the way I think it should be on next gen platforms for added graphics and mechanics)