Yeah, BFG was my GotY 2016, a real pleasant surprise, but...
Campaign needs to be more, I dunno, substantial. It was ok but just felt like there could have been more to it.
Balancing the different races with the different match types. Wasn't too bad against AI, and gave the game some nice variety, but against human players that know how to exploit different races strengths and weaknesses some match ups on certain match types were virtually unwinnable.
The skirmish mode needed more freedom to do what you want. Higher points values, have whatever fleet structure you like, allow you to choose upgrades etc so you can work out what works best in whatever situation, choose match type, choose what the enemy has etc etc. I don't see why any of that would be particularly hard.
Nerf Tau plz.
It could do a better job of explaining certain aspects of the game, especially such vital bits as the focus target button.