New maps. Playing the same 4 (more like 3 since TA is so boring) gets boring. I think making Combat Bay into a multiplayer map should be relatively easy, shouldn't it?
Class Balance. There are really two classes that are overpowered. Blaster and Tank. Blaster does probably the most damage in the game, has the most health in the game (along with Tank), and moves just as fast as a Striker class. Tank is sometimes literally impossible to kill. He has the neutron shell which makes him invincible for 8 seconds, the buckler which is another overpowered shield, and the highest defense stat in the game. Not to mention he can roam around the map easily. If a class has that much defense, it shouldn't be able to chase down Striker and Support classes so easily. So my suggestion: Nerf the damage output of Micro Munitions on Blaster. Seriously, that grenade is the most screwed up one in the game. Also, Rockets shouldn't stun opponents. It's super annoying, basically once you get hit by a rocket, you're completely screwed. For Tank, I'd make his neutron shell breakable after, maybe 5000 damage? Idk about the specific number, but it should at least be breakable.
Completely remove slide. It makes the heavy classes move extremely fast, while not being that much bonus for light classes. If you remove it, heavy classes will become less overpowered and light classes will become stronger.
Patch the hacks and ban cheaters. Probably the most important and need pressing thing right now. The game is being completely overrun by hackers. There's a good list of hackers on the report players thread.
New classes. Everyone would like to see a couple new classes. They make the game more interesting, and then there's actually something to spend Zs on.