8/9/8/9 (34/40) in Famitsu btw.
Diamond--which I reserved for day one purchase--was where I bowed out of Pokémon until testing the waters again with Shield (which proved to be every bit as lacklustre as I feared). I remember a Drifloon and a beach area, but mainly I remember it feeling heavy and slow to play and not much of an advancement over the first three games at all, despite the jump to DS. After a few online trades and matches with people here such as @Coolness Bears and the like (the headsets that Game bundled in made that aspect pretty novel!), I quietly moved on to other things without getting very many gym badges at all. I didn't consciously know my last time playing Diamond was my last time playing it, it just ended up being that way.
And yet I find myself side-eyeing these re-releases with their vile box-art when I see them on shop shelves. The pull of Pokemon is strong, as shown by the 6 mill these shifted in short order.