They should flesh out the race traits more, both inherent traits and race passive skills. Each race should have it's own amount of accuracy and stability so firing a gun feels different with each race. Stuff like that.
And they should do a better job in general with the power trees. Many of the evolutions for powers are just *useless*. For example, with Warp, there is no reason, EVER, to not go Detonate/Expose/Pierce, with any class, ever. Maybe if they had buffed the Damage and Cooldown options to the point where they actually make a difference they might have been worth taking on some classes.
And I think they should make the AI of mooks better and have more enemy variety. The mirror enemies in the Armax Arena gave a taste of what this game could be like fighting against decent AI.
And of course, there should be different game modes and better maps. --- You have one or more unread System Notifications. Please read them as soon as possible ^^ http://www.youtube.com/watch?v=ZEf5VFKplzw
After finally giving the multiplayer a go (had the game since launch) and really enjoying it, I'd like to see some co-op campaigns/missions that aren't just enemy waves. Maybe a few dlc length missions with varying enemy types/objectives etc..
In fact I'll go one step further.... I'd like a way to implement player made campaigns with an editor of some kind. Think the map editor in Far Cry 3 but without the terrain editor and some way to create your own objectives, player/enemy/weapon spawns....etc --- GT: Laser PeowPeow