Unfortunately, I don't have a Mac computer to try the game, but a user who tried it on his Mac computer, did a guide I hope and can be of help. https://itch.io/post/899079
Osu! is a musical game that is usually played with a digital drawing tablet alongside a keyboard, and is an amazing precision tempo game. Very tense, requires literal perfection if you intend on actually getting high rankings, but the rush you get from getting a new personal best is exhilarating.