Nice. I started doing the same several months back, but I wanted the map to be complete and had no way of knowing how many pixels wide the empty areas on either side of the map were, so I stopped right there rather than to be inaccurate. Silly reason I know, but I'm glad someone else is doing it.
I'm mostly looking foward to the four special maps: "A Beast of a Level", "MENACING!!!", "What an AWESOME Level" and "A BeastII of a Level". I loved the graphics and music of these.
If you stick to this to the end, are you also going to map the various expansions, namely "Oh No! More Lemmings" and the two Christmas Lemmings?
This also reminds me that I've never even played Lemmings 2: The Tribes, despite how much I wanted to when seeing the game previewed in an old PC gaming mag way back when.
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"With the first link, the chain is forged. The first speech censored, the first thought forbidden, the first freedom denied, chains us all irrevocably." [...] The first time any man's freedom is trodden on, we're all damaged. - Captain Jean-Luc Picard
B*tch, meet reality. Reality, meet b*tch. - Me