Daniel_M: There doesn't have to be outright thrashing for the negatives to be all too clear which is all that is needed
because we all know what we don't want a game to be like.
Luned: That's true. The reviews were very clear that there were many things they liked about the game, and some they didn't. They were a long way from "this game is completely awful", though, which the one-star review for the mistaken link to the Nintendo DS game pretty much did say about that older game.
It's fine to not like the direction the game designers took, decide that wasn't what you wanted to play, and get your money back on a preorder, but that's different from a buggy, unplayable game.
I expected to get pretty much what the reviews described---a slightly more casual game---based on the previews and developers involved, and that's fine for me, too.
Oh the German review for example was harsh, the author even (rightly) ridicules Poirot's exultation about having realised obvious things (he even mentions a scene with only 3 objects all of which had to be found).
BUT of course almost all hinges on your expectations (partly on what was promised too, or I wouldn't have pre-ordered). I don't want to bash the game, if people buy it and enjoy it, great for them, but it's sad for us others who had reason to expect something else.