A couple of UI things
First of all, I want to commend you guys on the development effort. Great stuff. If you're interested in how the game runs on some weird hardware, my specs are here:
CPU: Opteron 6276 (@ 3.1GHz)
RAM: 16GB @ 2133MHz
GPU: R9 390x XFX
I consistently get 140FPS, which means you guys did a commendable job at multithreading.
I found three things that I thought I'd mention. They're all more pet peeves than anything else, but perhaps worth mentioning nonetheless.
When the launcher-thing checks for updates, chat lags briefly. This is annoying if you're in the middle of typing something.
The loading screen shows the Options button, but I'm not able to click it. Presumably because loading is happening in the same thread as input/graphics.
Perhaps add a wait time to spam party invites.