Hey !
I've just gave the game a quick try and it seems that when the player is hanging on a ledge and I press jump, the player doesn't jumps higher enough so he can reach on top of the platform:
https://streamable.com/t4wwx
Edit: I forgot to say that I was using the gamepad, if I use the keyboard it runs fine.
Another thing is when I save the game, then exit to windows, then open the game again and continue, this is what is happening:
https://streamable.com/ztjox
bullet and weapon effect angles are messed up.
I would like to know what is the size of the background image and the other big sprites that you use in the game.