>>6982036A lot of layers in photoshop.
But basically get the assets you want (characters and a background). Get a 500x500 square with no fill, turn it 90degrees, centre it.
Duplicate the background, cut a square shaped hole in it, add your characters and then just fiddle around with the bits you want to show outside of the square window.
Not too happy with this one, background was kinda shit.
