Challenge Mode: Hype up Garbodor without mentioning its GMax form.
unironically one of my favorite mons so i'll take this one
First, getting the most common complaint out of the way: being "literal garbage" is not actually a problem or even unique to Garbodor. Trash monsters are a cool concept on their own and a staple in everything from RPGs to kaiju movies, we've always had inanimate object Pokemon, and we've always had "toxic waste" mons specifically, which i don't see getting the same hate (maybe a little for Muk but nowhere near as common or as vehement as the anti-Garbodor crowd in my experience). Garbodor even completes a trio with Weezing and Muk: we started with liquid waste/water pollution and gaseous waste/air pollution, and now we got solid waste/land pollution to round out the set.
All that aside, Garbodor's design itself is actually pretty rad. The walleyed stare, lumpy amorphous body, and little "ears" give it a "little kid's crudely scribbled drawing" kinda feel to it, which is adorable. i love the juxtaposition of that innocent vibe with jagged teeth (i always imagined them as shards of broken glass) and a decomposing body, complete with an exposed "skeleton" in those metal elements. The combination of comically cute and grotesquely monstrous traits is just incredibly appealing. Garbodor's face, pattern, and body shape/proportions even evoke the image of Totoro, only twisted from a nature spirit into a rotting garbage monster, and they've played with that imagery in the anime if i remember right. It comes off as an affectionate parody of an iconic character while still being unique and immediately recognizable on its own merits instead of leaning too much on its inspiration to give the design any meaning or appeal. It's tricky to strike that balance, but they pulled it off well. The asymmetry of the arms is a nice touch too, a little something to make it stand out more compared to other mons while playing into the whole "unnatural trash beast" concept and "child's drawing" look. The one thing I'd change if i could would be to give us a little more detail and variety in the trash bits sticking out of its body - a tin can here, a fish skeleton there, a broken toy somewhere else - but even without those finishing touches, Garbodor's design just drips with personality.
tl;dr the killer mutant dust bunnies are delightfully creepy-cute, genuinely fantastic monster design here. a real challenge mode would be Lucario or Indeedee, i can't think of a single good thing about either of them