That was actually pretty good. You lost in probably one of the two hardest parts so don't feel bad. I was the tester and it got even me quite a lot of tries actually.

And sadly yes, as it is so short checkpoints would take away from the difficulty. Because the jumping itself is not hard, the hard part is doing it after everything that came before it. So, we thought to better not have them and have a difficult game rather than a boring one  : )