Thanks for the feedback. It's really not that hard tho, one of the pieces is already solved so you can use that as a pivot (as you can see in the video).
It cannot be a normal slide puzzle because the images (the pixel art pieces) come in very different resolutions and you need to drag them around, that's the whole point and more than 1 actually liked this functionality. Also, many of the pieces are not too puzzle-friendly, there's areas of flat colors that would create identical tiles (so the dragging is a solution to that).