A very neat little game! The physics and animations seem to be done splendidly. A hundred little details that make it beautiful.
The only real gripe I have with it is that you can make bad choices that can't be easily reversed- that is, upgrading the orbs. The chance you get an orb of its given color is equal to the number of upgrades on that orb divided by the total number of purchased upgrades. The first upgrade for each color is necessary, but beyond that... you're increasing the chances of that orb over others. When it's the best orb you can afford, it's quite nice. When you've moved beyond it... it's dragging you down. Your endgame power is only as strong as your temperance.
I thought the prestige would let you redo your orb ratios, but nope, just the idle upgrades.
If I were to make it, I would've tried to skew the math to make it so that you can't make strictly bad decisions, just... unwise uses of resources that could've been put elsewhere. For instance, make each orb color take a percentage of the previous orb color's chance, based on your upgrade level. That way, upgrading lower tier orbs never decreases your overall money per second. In fact, it can significantly increase it, as increases to chances will be passed down the line to more valuable orbs.
RefriedBen10 below me seems to have the right idea, since they've only upgraded the final orb beyond the first level.
It's a shame when the most optimal way to play the game isn't the most fun way to play the game. I do my best to avoid that.
Seriously, though, you rocked the physics on this one.