Arrow keys to move, up to jump, hold space when it says to press the space bar. If you go offscreen you will be teleported to the middle of the screen, this is not a glitch. If you get stuck from the final attack pushing you into something, that is also not a glitch. The Final attack drains a lot of health when I play, so I would recommend avoiding the other attacks. :P
I worked pretty hard on this one, all the code is by me except for the basic platforming script, I don't remember what project it was first in but I got it from @LUIGILUIGI1. Song: Believer by Imagine Dragons Have fun! Scratch Cat Griffpatch WazzoTV Wazzo Slatch Super Mario Bowser Toad Luigi Undertale Sans Papyrus Mettaton Warriors Cats Creative Code Pen Cool Awesome Vector Bitmap Freddy Chica Bonnie Foxy