yeah, there have been an increasing number of third party games that aren't in "official" wii branded cases. it's not even about the company...
resident evil: umbrella chronicles = not official case
zack and wiki = official case
both capcom games, totally different cases. i haven't quite figured out why it's happening, but yes, it's kinda annoying.
even more annoying... games that don't keep the 'all white' look on their cover art spines... the bigs is all black except for the top that's a little white box with the wii logo, spyro is all dark purple even around the wii logo, lego star wars is all bright yellow even around the wii logo. way to ruin the look.
oh, but as for the discs. yeah, the monkey ball one looks like ass. only a couple other games have that same look though. most of them, even in just a couple colors, look really nice in that minimalist sorta way. vivid colors, crisp logo, nuff said.