I think I figured out the stretching: if I'm not mistaken, I believe what's happening isn't that the DOS version
isn't stretched - rather, the Amiga version
is stretched
vertically, but some of the graphics weren't resized to accommodate for the DOS version's lack of stretching. I'm making the assumption that the Amiga version's appearance is intended.
Hopefully I'm not being fooled by emulator defaults here, since I don't have an actual Amiga to reference from, but everything
seems correct. I believe the zoom is 100%, i.e. the emulator shouldn't be changing how big the pixels are.
First, screenshots of the Amiga version. In menus, the "pixels" of the image appear to be 2 pixels tall in all UI elements, while gameplay element (lemmings, terrain, objects) "pixels" are 2x2 pixels.
Here is the DOS version main menu:
Here is the Amiga version at 100% x 50% (i.e. undoing the suspected vertical stretch)
And here's the DOS version at 100% x 200% (i.e. applying the same stretch on the Amiga version to the DOS version)
This looks a lot closer to the Amiga version - even the font looks like it's probably the same, just with fewer colors.
The background image from the DOS version is therefore 320x104, but was most likely intended to be drawn at 320x208 when it was created.
I'm mostly neutral (leaning towards no) on whether we should resize the background in this way. Reasoning: the background and font don't have anything obviously wrong with them in terms of their sizing, even though both were likely originally intended to be drawn with the stretch.
A version of the background with this stretch applied is attached.