Cute and fun! The shadow blocks were a nice twist. I liked the bubble background too and felt like you did a good job keeping the screen lively.
On my first normal puzzle, I totally didn't see the one tower in a row by itself, then I encountered some weird bugs where if I moved the cursor down to it by pressing down, it wouldn't actually let me select a block, whereas if I wrapped right or left, it worked fine.
A pleasant game, but I think I want like one more mechanic like the shadow blocks to really stick with it.