Yeah just yesterday I was looking for something to play Google Music through on my new MBP, found Radiant, saw it required Flash and proceeded to move on. I'm on a 14 day trial of Gear Player, which seems nice but seems lacking for how I interact with my music.
It works well enough, has album art views, something I do want as a feature, but Radiant has a nicer overall UI (IMO), has a mini player that I can tuck away in the corner somewhere, and has the ability to add new playlists within the app. Installing flash is that much of a dealbreaker for me.
You should check again; it's tucked under the labs section but there's an HTML5 audio player available as a Flash alternative. Doesn't work in Safari though.
https://radiant-player.github.io/radiant-player-mac/