Press arrow keys or WASD to move (although all the levels are very easy, on account of just being one repeating platform) Press S to save your level number to your username. Unfortunately, this does not work for new scratchers on account of the "Username" block. Sorry :p.
Ok, the test has failed. It only saves one number to one username. I'm gonna try to fix that, but as of now this is useless, except at showing that one person (me) has saved one number (2). Maybe I'll look into cloud list engines. I wanted to test if it's possible to save numbers to multiple accounts using lists. This actually would work for things other than platformers where one might need to save a number to a username (if it worked :p). Currently there's no way to load, unfortunately. I've only shared this for testing purposes as of now.