I admit the title put me off a bit. The wrong preposition could signal much more serious problems. But fortunately the game turned out not just satisfactory but satisfying for me, even though some of the puzzles would wind up forcing me to wangle more than average.
The plot is simple. You, as a young kobold, fall off a cart and wind up in a human city. Since humans don't like kobolds, you need to sneak around. The first puzzle seems simple: find a disguise to blend in. Except it's not that easy! And that's where some custom verbs, along with USE X ON Y syntax (something I'm a big fan of), kick in. One custom verb in particular is clued and makes sense, and it's phased out as you solve puzzles.
You also have SEARCH MEMORY to see if you need to do anything in a location. It's interesting to require such a long command for hints--it certainly deterred me for going to spoilers. However, sometimes I went in for a spoiler when I didn't need to. I had the puzzle figured, but I didn't quite have the right syntax, so I wound up checking if I was on the right track. I was, and things seemed clued well enough, but this broke immersion a bit despite SEARCH MEMORY avoiding fourth walls. For instance, one puzzle requires USE X ON Y, but I didn't take X because X seemed kind of heavy and similar to another object I couldn't pick up. So I went with a bit of parser trial-and-error, but fortunately, there were very few errors to make.
There are also a few auto-deaths with timed puzzles where humans are getting closer. You just have to leave and return to reset the timer, but it's enough to create atmosphere. I wound up running ahead too fast after solving one non-timed puzzle, not realizing a useful item I left behind. So I thought "okay, okay, timed puzzle" while it happened, but it had a knock-on effect: I was that kid, running ahead, looking for their family, not taking the time to get centered and see everything that could help.
The timed puzzles start out pretty easy (just take something and leave) but the final puzzle requires a bit of prep beforehand. In one case, using a verb with an implicit object not only gives a reject but uses a turn. That's not too bad, as you can auto-save, but it's not very hospitable. I also worried I'd gotten in an unwinnable state when I seemed to have consumed an item I didn't, due to a reject message ((Spoiler - click to show)the game says you burned the plain stick, though it's still in your inventory).
Nevertheless, what was going on was pretty clear. There were a few "you can't quite do that" moments that forced me to make logic leaps that were generally pleasing once I pushed on to the next room. And while it's pretty linear, there are clues of side locations once you're stuck, and you'll realize you're stuck. The final puzzle has probably been seen and done before, but it's well done. At what I didn't know was the final room at the time, I felt the game might be ruined if it dragged on too much. There was potential for a maze, but the author cut things off, and it made for a strong or at least tidy ending.
So KiSfF has some rough spots, enough a post-comp release could boost it nicely (lots of parser clarification, implicit verbs and verb synonyms, and also custom bits like changing the RESTART from the generic "Would you like to forfeit the game?") but they're the sort that I think if you know of them ahead of time, you'll be prepared to sit back and enjoy it. And the tutorial does a good job of showing you what you can do.