Hey, thanks, glad you like the game! :)
Nice to hear that the controller seems to work, I test it all on a super cheap generic controller myself. (it had a price of around 3 dollars or so)
As for the borderless fullscreen issue, I'm not sure there's much I can do about that for at least two reasons:
1. I can't really test the game on windows 7 right now as windows 10 is the OS I use, but the game should work just fine on windows 7 which is why I put "windows 7 or higher" as system requirements.
If I get to a better living situation I could put windows 7 on my other computer but this will probably not happen for the foreseeable future.
2. The game is not actually running in borderless fullscreen, it just runs in a window that is the same size as your screen which in turn hides the borders.
No clue how other games do this but this was the only native way I found to do it with Game Maker.
For the room issue, this happens because you entered a room that does not exist in the demo.
The way you reached this room is a bug that has been fixed in the internal version.
As for save points, there will be a closer save point in the full game. ;)
And aiming straight up/down while ledge grabbing is on the to-do list but I'm still not sure when or if it will be added.
Anyway, thanks for the feedback! :)