I absolutely loved this game and all its little secrets. I did get to the ending, but had to do a little decompilation work to figure out the very last step. This makes a kind of sense in hindsight, but I don't think was very well-telegraphed at all; for posterity, to trigger the endgame, you need to (rot 13) perngr guerr be zber ubzbaphyv (gur uhznabvq barf--vs lbhef vf n oybo, lbh unir nabgure fgrc gb tb), naq cresbez nypurzl ba nyy guerr jvgubhg orvat va gur pvepyr. V guvax gur vqrn vf gung guvf perngrf n 'onynapr', fvzvyne gb 3-rffrapr bowrpgf orvat onynaprq naq fgnoyr va gur erfg bs gur tnzr, ohg abguvat ernyyl yrnqf lbh gbjneqf gung.

Incidentally, several of the trap doors appear to be broken, particularly those revealed by expoding cracks in the ground. It looks like their teleports aren't set up correctly.