Clever mechanic with combining things to blast blocks for points and free up space. Nice work!

It's well made. Had no issues with the controls or the menus. 
I realised early on that you get long (+)  droughts, so you have to be a bit strategic where you place it to allow more time to build up a large area of destruction. Maybe you could include some hints in the how to play section. 

I think if you added a more interesting background it could help make the game feel even more polished.

Well done! I think it's a good game despite its simple appearance.