Very fun and chill game, you did a great job of creating a satisfying game-feel.
One potential exploit I realized is with laser and ufo, both run automatically without needing to launch any more balls (aside from one to hit and activate the ufo). This allows you to AFK and rack up infinite points without ending the round. Maybe a fix would be having the laser/ufo timeout after x-amount of seconds after your last ball launch to force the player to keep playing.