Thank you for your feedback! No, you definitely didn't pick stupid, the skill order just hasn't been balanced yet. I'm sorry you got stuck, but I really appreciate you commenting and giving it another go!
This weekend I've been pushing out optimization patches, but my next goal is to iron out the gameplay loop and put together a satisfying progression curve. I'll post an announcement alongside each major update!
I've been thinking about upgrades and thought briefly about collisions between balls and higher power launching and think that's a dumb idea. You have a very nice amount of force and gravity here. Gravity does affect it, but it's not super powered. If we start changing ball speed, the gravity will have no meaning and I don't think it's worth the loss of the balance you have between force and gravity.
Little robots to go pick up the blue gems for you, or a magnet or extra range upgrade on gem pick ups are missing and would be appreciated. Even an upgrade to get half or 10% of the gems on the ground at the end would be close enough. This does need something to pick up the exp.