Pretty hectic and addicting!
I didn't get to use the store page because I lost to the boss when I clicked on it. I suggest having it come up automatically between waves or pause the game when in use.
Some sound effects were unusually loud, perhaps they were playing multiple at the same time.
Using keyboard, I felt I lacked some precision on picking up the squares, so that part felt random.
I liked the shooting and all the weapons felt very satisfying on mouse, and hitting the enemies accurately was a good feeling.
Good work!