I've played through the demo (which does not include this puzzle) and read through this thread, and aside from the issues mentioned already, I have an issue with the word "resembles" in this context. While the guy whose head looks like an onion is meant to "resemble" the onion rings, in my opinion, raw onions don't at all resemble onions which have been sliced into rings, battered, and cooked into onion rings. Similarly, a buffalo bears no resemblance to a hamburger, even if the patty in said hamburger is made from buffalo meat. "Resembles" is too subjective, and a logic
puzzle, of all things, shouldn't have anything subjective in it. If the guys' names were Onionrings Jones and Buffalomeatburger Smith and the clue were "nobody had a dish with the same name as their spouse", I might be more appeased by this puzzle. If you make another Puzzle Agent, I highly recommend having the puzzles passed by some of my cohorts in the puzzle community who are really keen on semantic issues like this.
To tell the truth, for reasons I cannot really articulate, I tend to enjoy a well-constructed pencil-and-paper logic puzzle more than the types of puzzles found in Puzzle Agent and Professor Layton. As such, I'd rather buy any of the DS titles in Nikoli's Puzzle Series (especially Slitherlink) than Puzzle Agent. What I'd really
like to see, though, is a second season of SBCG4AP.