I have some ideas what could be added:
- A difficulty mode between easy and normal (make orb sizes the arithmetic mean of easy mode sizes & normal mode sizes)
- Add a save button (I wouldn't mind if saving quits the game, and loading deletes the save file, similar to roguelikes)
- An indicator how often you managed to combine 2 orbs of the largest size, s.th. they completely vanish
- Adding Mouse support: Left-click drops an orb where the mouse pointer is
- Allow to decrease breast size