It... actually works! :O
I just recorded me playing the game with Win + G (tho it would have been ideal if I could've recorded my first time footage, because now having fought the boss before, I totally massacred the boss XD)! I was actually prepared to download an actual screen recording software just in case it didn't work
So far from the ones I have played, this is the submission with the most effort put into it. Expect it to be in my let's play ;)