Nice game with some tiny flaws though, I feel the one button mechanic fits the theme perfectly and this makes quite some potentiel for a mobile version as well, having the left and right borders of the screen kill you is a bit overkill i.m.o i'd say maybe either have them make you auto change direction, or appear on the other side ( like in mario 2 NES for example) this could add a bit to the mechanics, also having the jump on the button hold makes it a bit hard to chain jumps that are too close to eachother, i think this aspect could be improved by changes in the level design to better suit the mechanics.
Other than that i had a good time with your game, cheers and congrats :)