User Interface:
- You should be able to open your inventory with "I"

- It needs to be easier to know how to read your hero abilities during character selection

Gameplay:
- You need to improve hit detection when you aren't the host.
- You should add "directional turrets". These would require you to place and then rotate them so that they have a line of sight or cone in the desired direction.
- You should add economy upgrades. Things like spending large amounts of a resource to boost production in another resource, for example. This adds some depth that I think could be positive.

Bugs:
- Many character quests are not progressing in multiplayer games.