Finished the game a couple of weeks ago. Personally, I loved it. I even managed to convince a fellow student to get it, when he asked me for good overlooked Wii games you can get for cheap. He enjoyed it, too. ^^
Some bosses really were a bit of a pain. Especially those, who had instant kill moves. :P
Couldn't be bothered to get all collectibles, but thats the case with every game for me.
How can I take Verde to the last battle? I can't remember having the option.
My only technical complains are the lack of pointer control, clumsy group management and the lack of 480p. Neither killed it for me and the game controlled well enough, but seriously, what were they thinking when they decided not to include the pointer functionality? Some "shake the mote for sending all minions with the same class as the first one at once" command wouldn't have hurt either.
It uses real world art and themes, that you could describe as mature (at least as mature, as the 1001. whack-a-mole WWIII shooter, anyway), and packs it into a... well, that would be a spoiler.
I'd describe it as an extended playable fable. There's lots of subtle irony in it and if you are so inclined, you can well call it art. Plus, the game's mechanics may have elements of Pikmin, but they're really quite unique.
Looking back, I can see why the game is so overlooked. When the creators deliberately chose an art style like a child's fantasy, they practically asked for it. I'm just happy the game came into being and sad, that only so few people will look past the visuals and enjoy the game they hide...