It's really unclear what's going on.

I'm just sorta mashing buttons.... If the green buttons are like "Buy one and it's done" then you should not have them react with a bouncy effect when I click them. The bouncy effect is a signal to the user that clicking on them is having some impact.

There's a prominent 'Planet' button and a 'Biology' button. But clicking either does nothing. It's confusing why they're there, or what (if anything) they do. I played enough to unlock the 'Tools' button, too, and that one makes sense.

But still.... I'm just mashing buttons. Lavendar buttons. Clicking something of any other color has no effect. Just click on what's lavendar.