Thanks for playing! It was fun watching your playthrough. I actually recently updated the game to make that last stage a bit easier. It saves progress, so if you re-download it, you should be able to skip straight to the last stage if you feel like giving it another go. As a hint, Everett needs to be alive on that ledge. You can use the upside-down checkpoint and some post-respawn momentum to get up there, like in the last puzzle of stage 2.