Nice little game! Few things i noted though, the platforms are a little too slow and i'd prefer to have the jump on either space, W or up arrow for a couple reasons: i'm in a very uncomfortable position cause i have to hold both hands on keyboard and so close to eachother, and most platformers do that so it took some time to get used to. Could just be me not used to keyboard only controls, but you could still include W and space as options and still keep J as jump if you so wish. No other complaints, overall not bad! Good job! :)