Garry Francis has a good system for taking a concept ('mystery in a high school', 'searching for the holy grail', 'fairy tails') and turning it into a tersely-worded parser game on a grid-like map with traditional fetch-quest and lock-and-key puzzles. His games are consistently well-coded and are generally well-received.
This game is one of the larger of his games, and it is very open-ended. I and a few others ended up exploring large portions of the map before discovering key items we needed very early on. The game recommends drawing a map, and so do I. It's also useful to look under things.
The map takes us across plains and hills, ponds and cabins, cemeteries and crypts. I once made a game with a horror area and, to instill that horror in players, used the scariest thing I could think of: diagonal directions. Here, the author has made the same decision, with numerous diagonal directions possible.
Once I found the necessary items (I found it useful to use HINT in multiple locations; it is location dependent, which I didn't realize), I found the finale gruesome, but satisfying. I do wish in some ways that the game were either more terse or less so; at times there are descriptions of reaction and emotion, and at others none, giving an odd disparity.
Whether due to Puny Inform or the author's own choices, the parser can be petulant, a feature I've seen a few times in this author's punyinform games. By mimicking an old school parser's features when new school features are available, it can give the feel of instructing a toddler who is not very motivated:
"Johnny, can you go east?"
"But there's a door in the way!"
"Johnny. It's okay. Open the door, and then go east."
or:
"Johnny, can you pick up that rock?"
"But my hands are full! Wait, let me see." He takes off his backpack and rummages around with the items in my hand. "Can this grapefruit fit in the backpack? No. Can my dinosaur toy fit in the backpack? No."
You are waiting patiently.
"Can my coin fit in the back pack? Yes!" He puts the backpack back on and struggles to his feet. Then he bends down to pick up the rock. "I did it! I picked up the rock."
or:
"Johnny, can you look up 'abracadabra'?"
Johnny looks at you very seriously, and says, "You have to say, 'can you look up 'abracadabra' IN something."
Me, looking at the only book in the room:"...can you look up abracadabra in that book right there?"
"Okay!"
or, finally:
"Johnny, can you write 'hello' on the paper?"
"I don't have anything to write with!"
"Oh, Johnny, where is your quill? Look for your quill."
"Here it is!"
"Where?"
"In my backpack!"
Me, increasingly frustrated: 'Can you take it out of your backpack, Johnny? I was hoping you would do that yourself."
"But my hands are full! Wait, I have an idea." He takes off his backpack and sets it on the ground. "Will this grapefruit fit in the backpack? No. Will this plushy fit in the backpack? No." Johnny looks up at you with very serious eyes. "Sorry, I can't pick up the quill. My hands are full."
Besides that, I thoroughly enjoyed the game, and expect that most people that play parser games on a regular basis will do so as well.