The platforms needs to be placed a little bit lower since it was rather annoying that one couldn't get up due to the jumping height not being enough. The third level I think it was, it took me like 4 times to notice that I had to go below the enemy to move the box on the other side which made apparent the problem of jumping.
To not have to change all the levels, then just tweaking the jump to be a little bit higher would have worked better.
I managed to beat the game but it was a bit tricky to manage it due to the jump not always reaching the platforms.
Everything else was great, I wasn't expecting to be the coin that I had to run away.
And I liked the animated intro, it was a nice touch.