I'm about halfway done with this game, but I'm going to wait until I'm finished to post any full map.
However, I've run into a small problem with Jupiter's stage. Toward the end of the stage, you eventually reach a point where you can either climb a ladder or go to the next screen on the right. Going right leads to a final section and then the boss. Going up leads to a couple of items and a dead end, but when you come back to the intersection, the passage on the right is now closed and a new hole is there in the floor which leads to a special crystal, and then to that same last section and the boss.
I can see two ways to represent that which I'll post below.
Method #1 - Using arrows to represent how you can move in this area. It is more accurate and shows the intersection (the left-most screen) in both states, and how both paths lead to the same section and then the boss. The downside is that it's cluttered with all the arrows and not easily understandable at first glance.
Method #2 - Simply show the screens as they are attached to one another. The advantage is that it's a lot easier to understand, and you just have to suspect that there's some way to open that passage down. On the other hand, this method leaves the player to discover by himself that it's going up that will open the passage downward, and the duplicated area with the boss might lead to thinking that there's a real and fake one, like in Mega Man 6 (NES).
All in all, I prefer Method #2 because it just looks better, but maybe some people might prefer the first one, or perhaps someone else has a better idea.
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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
Current projects: Mega Man V (GB), Mega Man Zero (GBA), Battletoads (NES), Sonic CD (Sega CD)