Playtest build 600 - Multiplayer compatibility with the demo

Hi everyone, I just released the latest playtest build. This contains performance improvements and better support for high res monitors. Additionally, it has the ability to host games to play against friends that are playing with the free demo version. The demo launched yesterday, so with this change playtesters are able to play against any of their Steam friends! Have fun! And as always, if you encounter any issues, feel free to reach out to me on Discord.