This will be very stream-of-consiousness, need to run...
Want to see that mining laser physically affect what youre mining, just new sprites on the rock would be a start
make the energy indicator on your hud pulse when youre in a charge area. have another one appear beside if youre maxed to inform you of this
More VFX to show that youre beat up (staticy hud, cracked glass, etc...---look at HAWKEN with how they went about it)
needs VFX for impact of enemy weapons and a directional damage indicator (lurching of hud, shock of static) This is super important information to be giving to a player
Radar needs a dark background. It easily gets lost in the noise. Have it chirp once softly when a new enemy appears
Constantly beeping homers change the meta a little in that they give away your location when fired.
Can we have it so they only make that beeping when they have a lock on something?
Make the mega explosions a little less spritey somehow? it looks incomplete when it clips threw the wall
Hit indicator sounds? Like the new kill confirmed sound
Pudlez raised a great point about inadvertently siloing players from eachother who have different tech levels. It would help players around during thin periods to maybe have game with a "tech-limit" like in Command and Conquer, or have a range of allowed tech for that game? It would automatically down you tech level for that game.