you go to the middle where there are a few blue platforms. you jump on them. as you (the player) go upwards, more platforms spawn. you just do parkour from platform to platform.
infinte, to a certain extent. eventually, if you were at like level 10 billion, you would run out of CPU space but I can assure you, you probably won't reach a high enough level to fill your CPU.
The code makes new platforms juts above you so the higher you are, the higher the platforms will spawn.