~Doom II

Level confusion sorted, via NetMail.

Anyone any idea why at the end of level 32 I end up back at level 16?
Is it meant to do that? Or have I missed a secret room or summat?

That's 'cos you get to level 31 & 32 from level 15, so once you've 
done them you should progress to 16. They're the secret levels.

Haven't been *CHEATING* have we? If you haven't, you would have 
known this......; I'll tell you how to get there properly, but I'd 
better SPOILER it or someone's bound to winge at me. Here goes:
  
AFAICR, to get to level 31 from 15 you must drop off the centre block
onto the small pillar in the lava; press the button and proceed to 
the far north of the lava where you should take out the cacodemons. 
Somewhere in that chamber a line trigger occurs which opens the 
entrance to the secret level; it's down the dim lava-filled passage 
in the bottom left-hand corner.

Since you obviously know about IDCLEV, you could always use IDDT to 
find this yourself.