Weirdly addictive game, I found myself playing this quite a while, even if the levels are a tad bit short.
There's a lot of room for mastery, which is really cool to have in a game made in such a short timespan. The Layout feels a little cramped, but I see it as an extra challenge to conquer (Although I have to mention getting stuck under the lower blocks in the jump section of level 1, really frustrating to experience that on a good run.)
I have to agree with JHawk though, resetting levels was kinda janky, especially with the escape button kicking me out of fullscreen mode. That Shift + R keybind mentioned below would've been nice to learn about in the tutorial, but whatever. And the countdown beeping got on my nerves after while, it sounds a bit too harsh in my opinion..
Nitpicks aside, I can picture this as a fully-fledged game easily, hope you'll continue work on this!
(I have beaten all your times and sub 40 total is definitely possible)