It should work on Windows, Mac, and Linux.
The game has a subreddit where users report bugs, request features, and also post roster/team/champion files. You can see a collection of the best of those posts here:
Feel free to report bugs by whatever method is easiest (Steam, Reddit, Discord, E-mail).
Sometime within the next week I anticipate starting to take feature requests and trying to determine which to prioritize.
Thanks to everyone who has beta tested, reported bugs, and created files!