OK, at least you recognize "style" in an overall context.
Now stop confusing the *over-abundance* of a graphical technique with the amount of effort put into the game's visuals. Wind Waker, VJoe, Jet Radio, look the way they do cuz they have so LITTLE cel-shading to begin with. Whereas killer7's world is pretty much influenced by the technique from top to bottom to create the freakish pop-art look. Killer7 is not trying to convey invidivual cartoon/anime/comic characters on top run-of-the-mill 3D surfaces (or sprites) that the other games are doing. That's something you should've already recognized. Those other games have it easy, they've got the candy-colored visuals people have no problem eating up.
It matters not if you don't like the game's style. I just didn't like your reasoning.
The rest of us here who dig the game fail to mention it's more than the looks that satisfied us. It's the overall atmosphere. You simply haven't HEARD how the game accompanies its visuals, and a bunch of other minor junk that doesn't get conveyed in screenshots and review scores and the like. Hell, a lot of here (years before you showed up?) were on the fence about the game and didn't eat it up until it was $10 at gamestop. Initial attraction wasn't strong, most of the interest was in heresay, and Nintendo wasn't a big help on the 1st-party front at the time. At first it was "eh, it's only $10, why not" (sorta like Katamari after the price drop, but you don't see everyone rooting for those sequels). They openly support killer7 now AFTER having played it thanks to recommendations from manipulators like myself.
I can't speak for GP tho. She played thru a "bad" 20 hours of killer7 yet wouldn't finish a "fetch quest" in an "infinitately" more "playable" "masterpiece" called "Metroid Prime." Does not computer.
Metroid Prime 3 is the easiest, most linear game in the Prime series anyway. It's Malibu Halo Barbie for non-gamers.