Writing about Picross 3D turns out to be more of a challenge than expected not because it's not a fantastically inspiring game, but because there's little to be added that Margaret Robertson didn't already lay out succinctly in her Offworld writeup of its import debut over a year ago.
We were obsessed with it then as much as I have become re-obsessed now, not just because the lineage of logic puzzles that came before it have remained an underdog favorite genre, but because it truly is -- as Margaret said -- the world's best representation of an entirely under-realized game design verb: sculpting.
Borne of Nintendo's original reimagining of the popular pen-and-paper logic puzzle pursuit known as nonograms (well before sudoku would, somewhat unfortunately, claim the ultimate logic crown [nonograms honestly being the more stimulating and rewarding game!]), Picross 3D is the Michelangelo equivalent to the original Picross series' semi-Seurat-ish pointillistic painting.
Which may be one of the most convoluted and thin-stretched metaphors I've ever made, but here's the logic: where Picross is an additive game of matching numbered cross-referenced instructions to their dot-placed ends (as at left, where you're told, "this row needs three dots in a row, then skip some space, then two dots together, then skip more space, then four dots together"), Picross 3D is one of subtraction, where you start with your massive granite block equivalent and carefully whittle it down until, awesomely, a low-poly puppy pops out.
At its best, Picross 3D is in constant dialogue with you, the player. Starting with your opening block, you knock out any row or column that's marked with a zero. Because of that, the game tells you, you can now begin to devise your next move. Does a row marked with a '3' have two adjacent blocks now standing alone? Surely, then, the three adjacent blocks the game is telling you are in that row can't be located there -- clear them away. And then repeat: what did knocking those two blocks out tell you about the rest of the columns and rows?
It's a succession of spatial-logic "if... then" statements that's extremely hard to properly express in words, but when you've learned its language it's as magical a conversation as you've ever had with a game, and one that only occasionally falters when the game speaks too fast for you to keep up with.
But so this doesn't ultimately come off as simply a pursuit of slide-rule/pocket-protector-ish number-play, Nintendo have quite wisely put an emphasis on the final result. Every finished work is an every-day object placed in a series of collections -- office accoutrement, travel accessories, traditional Japanese new years festival goods, and, of course, puppies, all with custom reward animations that snap the Lego-like constructions into focus.
It's as equally hard to explain just what makes Picross 3D such a potent puzzler as it is to do so while avoiding repeating everything Margaret tried to tell you a year ago, so suffice it to say that it's a masterstroke of a thinking-game on Nintendo and developer HAL's part, and, as an unintentional simulation of the masterwork act of chipping away to produce something beautiful, entirely unmatched.