Thanks for dropping a note! Yes, I realized it might be tough. I tried to keep the endgames as simple as possible. But I forgot even king and queen vs king is not trivial, even for smart adults who've seen it before! (Streaming chess events seem to bear this out.) For people just learning about chess endgames, it is rewarding--and they should feel good--as they figure out checkmate with queen and rook, two rooks, queen or rook. (Rook is hard. https://lichess.org/practice/checkmates/piece-checkmates-i/BJy6fEDf/VeKiltmx has basics if you want to try.)

I also think having the knight moves added more of a layer of difficulty than I meant it to have, but the game seemed too vanilla otherwise, and I wanted to do something special with the parser. And I wanted to get that final puzzle in.

I'd like to think that the difficulty was partially a matter of presentation. The puzzles could be made easier if the game supplied the player the right hints more directly e.g. "put the king in the corner." I also think it would be useful to allow the player to see what squares were unguarded and why they failed after each trip.

But I think I have a legitimate blind side: as a Fairly Decent Chess Player (TM) I automatically logically reject certain tries and wonder if the puzzle is too simple--forgetting how it was when I learned chess, how it wasn't cut and dried, and how I needed to make instructional mistakes. I think that also applied to the final scenario, sadly. I said "aha, if you notice <SPOILER>, it's all over but the trivial grunt work!" Forgetting that people who don't enjoy logic puzzles wouldn't think to look for <SPOILER>. And they might not see the grunt work as trivial.

As for other puzzles ... I think I found a few that are legitimately interesting to seasoned players and relative newcomers alike. And they have a sort of story. But that would (will?) be for another competition.

A competition where I wouldn't have these ideas two weeks before deadline!