You're right!

• The clicks not registering was something I noticed as well, though more on the clouds than the moon. The moon is really hard to click when it gets small, I thought of making the "Minimum Size" of the moons bigger, but I wanted to make the player jump from the planet to the clouds and the moons, which would probably not be the case if you could always click the moons :) The clouds on the other hand are really weird. Apparently, the cloud particles sometimes get out of their hitbox shape which is quite annoying, but yea, that's a thing I have to fix for sure!
• Music would indeed be very nice! I didn't have much time to work on that, but it probably would create a much more relaxing atmosphere.
• Showing the user all the possible features, like the dimension auto clicker, is really good advice, I didn't think much about that. A mini-tutorial could help there or something to make the buttons pop out

Anyways, thanks for playing, I'm glad you enjoyed it! I'm definitely going to work on some of the stuff you suggested :3 (Though after a break, the jam made me sacrifice every minute of free time I had lol)