Side to side is left and right arrows, jump is up arrow. it's not really a platformer as it is a test in patience. But still, it was harder than it would've been if I had used the full scheme of blocks.
I definitely bent the rules a bit to accomodate the average code, but it's still pretty bad. Without making blocks or using variables, it was hard to make the background switch or to have smooth jumping. But if you have suggestions, put it in the comments!