I have installed Earth 2140 (on MorphOS 3.7) and it wouldn't work out of the box. It complained about missingCyberGraphX and a defined 640x480x64k screenmode that was required. In case anyone cross this error in the future, the solution is to patch it with E2140_English_020401.lha file. Seems the archive cannot be located on Runesoft's website, so I suggest a quick google search.

On a side note, I 've tried to install the MP add-on but the installer quits without any actual installation right after the its welcome screen. Any idea why? If I copy and replace manually the files will that screw up my Earth 2140 installation?

@Yasu

Btw, in case you still haven't successfully installed Gish I can help you with that.. the usual way ;)