Great WAD, solidly nails that fantasy castle crawling feeling, not too rough on the player nor overly stingy/generous on supplies, encourages good use of items, plenty of navigation and switch puzzles as is apt for Heretic, but also lets loose with a little slaughter.
Some areas could use slightly brighter lighting, and sometimes the next switch or door isn't signalled too well, but overall a fun and feisty fantasy fight fest.
These levels are short, sweet, and pack a lot of punch. Complete with a humorous end-text-screen containing a healthy dose of silly shock-humor, this is a masterful triumph of Heretic map-making, and most certainly a must-play wad.