Lazyone posted a bit of news regarding the port of Wolf3d to DS:

I finally got my sub screen tests done so hopefully it can all be just dropped into the main wolf3d sources

I did have to change the backdrop a bit because the original did not convert to 16 colors very well.
It uses all 4 background layers:

bg0 - Backdrop
bg1 - Status bar image
bg2 - Status bar text
bg3 - Automap

The face is done using sprites and so far seems to be working out great

http://forum.gbadev.org/viewtopic.ph...eb292ca76aa394