Elements

>INVENTORY - Paul O'Brian writes about interactive fiction

So good implementation is a must, but a pure puzzle game could probably get by with a few minor bugs, so long as they don't ruin the puzzles the way the bugs in Elements do. I would argue that the most important piece, the one overriding quality that a pure puzzle game must have in order to succeed, is good puzzle design. Sadly, Elements lacks this crucial factor as well. I suppose it's just barely possible that someone might struggle through this game without recourse to hints, but I doubt such a person exists.