Fun game! I like the upgrading trade off, at first I was just spamming the upgrades but then I realized I actually had to think which is the needed upgrade for the following level.
I do advise to have a way to reach the controls of the game after the start, or at the game page. By the time I got to the 2nd level I forgot how to break crates, and I had to refresh the page to restart the game for the controls.
But besides that, it was a good time. Good job! :)