Didn't see anything similar like that so it was quite a unique concept, simple but fun to play!
At the beginning it was a bit too hard for me to coordinate my hand (6 buttons were too much for my brain :D), but after few tries I got a hang of it. After that I was hooked to reach higher and higher score.
Also, I liked that you added colors for each different size inside the shapes, it helped me to get correct size much faster.
Overall great entry, keep it up!