Fun implementation! But…
If the launch angle is too shallow, the balls never launch at all. The number of available balls just decreases without anything else happening.
I’ve twice had the game become unresponsive to interacting with the launcher, once at level 40 and once at 10. Other things still work, like the Gift button, but there’s no way to launch a ball. The game has to be restarted. The first time there was even an extra ‘phantom ball’ that stayed stuck on the launch line into my next game, and I had to completely close the app to correct this.
Hopefully you can get these issues corrected. Thanks for an entertaining game!