Right now you can sign up to beta test the iPhone version of the game. iPad, macOS & tvOS will come soon!
The game uses my brand new Swift & Core Animation-based game engine, so any feedback you might have in terms of frame rate and overall stability would be greatly appreciated! Also let me know if you have any suggestions on how the game can be improved in any way. Either reach out on Twitter @johnsundell, or by using TestFlight's feedback email feature.
Note that I can't guarantee that you will actually get a TestFlight invite, but I will do my best to get as many people on it as possible. Thanks for your interest and I hope you enjoy the game! :)