Renegade Kid's Treasurenauts looks like another great match for the 3DS eShop. And, more than that, like exactly the type of game that this team knows how to craft. There's a strange joy to be had in collecting a bunch of stuff in games, and Treasurenauts seems to have that panicked "Oh sh*t! I need to hurry!" angle (see: Sonic the Hedgehog) going for it.
Speaking of which, I could never finish Kirby's Epic Yarn. Not because it was too easy -- far from it, actually. Even though you couldn't "lose" in the traditional sense, getting hit would send gems flying every which way. And after a point, my collectible-obsessed self couldn't handle completing levels without that damned gem bar maxed out. Silly, right? I agree.
Hope that won't prevent me from liking this game, because it looks right up my alley.