Yeah, it's not even just that it stops you from getting up on the ledge, but if you're short-hopping or at the top of your jump arc, you can hit the bottom or middle platform, respectively, which stops you from continuing toward the edge of the screen. Probably not game-breaking for now but given fall-through platforms are so common I can see it being a big issue eventually.
It is feeling better overall, though! 60 FPS is maintained unless I drag the window around (it can go from 56-62 when I do that) and after some more tuning and refining the combat I could see it being pretty fun! Definitely would love to see those grapple attacks mentioned in the readme file eventually. Do you plan on having some enemies that make you vulnerable and grab you to do damage, or is the grappling just planned as the way you end up in game over state? Might be fun to have some that do sexual submission holds leaving you wide open to other attacks or inviting another baddie to come join the fun~