It's certainly an interesting concept with fun visuals and music.
I think a floaty jump would've matched better. Having such a small range of movement with such quick instant death limits the mechanic and makes it more annoying than fun. Besides that, whenever you have a random element in your game it's really important to consider the range of possibilities your random allows. In this case, I think your function for randomly adding things to the screen should've checked what was on the screen and made sure there's always a good thing to go after, if only to lessen the downtime.
Also, allowing w to jump would make controls a lot more comfortable. I know space is used a lot with wasd, but when w isn't being used for something else, it makes for a great backup when using small keyboards with large hands and such. It's also more intuitive if the player is used to games that don't use the mouse.