Great game!
As you said so yourself, the curving mechanism could be more clear. If you keep working on it (which would be cool since it is a very nice game!) you could try adding a 'reset spin' since it is difficult to find the zero.
Last but least: Great UI, feels super polished, really nice!
(i am always commenting on this i feel since i suck so much at UI, except for this jam, this time i just could not work on the game anymore and had to keep the temporary UI :)