This is an awesome game with great potential. You really nailed it. With some more polish, a few more features and performance tweaks you should make a full version of it and release it all platforms. I also liked how the blocks have soft body physics instead of being just rigid blocks, that's a really cool detail.
Great game. Enjoyed playing it a lot.
Just a few suggestions, the filter makes it bit hard to see where exactly you've placed the blocks so make it more transparent I guess (but this maybe just a problem for me). Also, a pickup or remove mechanic for a dropped block would be nice so player can rearrange their setup without a full reset.
Keep it up.