...I'm thinking of asking that old friend if he still has the disc and try to do something with it.
About size and themes, I'd say average Q1, I seem to remember that secret level 1(Purgatorium, as we have learned), accessed from where once was Ziggurat Vertigo, was blue metal in style, with lotsa scrags...
If you're interested in this version, I'd suggest you give a look at the document about cheat codes (
http://files.filefront.com/Quake+1+cheat+codes+in+detail+PC+N64+Saturn/;2607167;/fileinfo.html ) it has a good section about Sega Quake and offers nice comparation with the other 2 versions.
Colored lightning, they were thinking "Hey, we can make this look like Quake2, it just came out, people will love it!".
They made it look like Barnum in Hell, instead...
Oh, well...
Now, if I only can find the number of that friend of mine....