Simple, but ok concept :) -good job for submitting! :)
I would love to see some audio-feedback from pressing buttons -Maybe even the heavier ones could have a subtle hint that they are heavy through audio?
The visuals could also be improved, there are alot of free assets on the internet if you know where to look (unity asset store has alot of free assets)
To make the placement of squares more interesting, you could add a drag/drop mechanic to make it feel more like a game :)