one million hours in paint.net
I don't think thats the forest temple, there'd be overgrown plants on the walls and it would be a bit more darker if it was.
Probably a cave or ordeals type of thing or a bonus dungeon.
It's definitely fake. That looks nothing like a modernized SNES and is definitely nowhere near the size of a 360. Either that's a fake or multiple descriptions of the system are totally wrong.
god they've reused the same legendary pokemon fights other legendary pokemon cliche ever since the 1st d/p movie.