ENDLESS EXPRESS v0.6.3 - Day 1 hotfix + MacOS and Linux support

First of all, thank you to everyone who've played Endless Express since the release yesterday (and everyone who will play it after too)!

Pushed a new update for Endless Express meant to fix some bugs with player usernames resetting and being overall annoying.

Also added a popup window welcoming new players and letting them choose a username (it was actually here before but didn't appear due to a bug).

Lastly, I added a small "dev message" on the menu that I can change at any point. Useful to communicate with you guys if a new bug appears while I'm out.

This update also brings support for MacOS and Linux!

Thank you for enjoying the game, and for the nice comments!