I haven’t actually added up all the puzzles that there are, but it’s over 150. Probably 200-ish. But now, they’re all done!
I was expecting another set of puzzles after completing the Star ones, since there’s a gap on the screen where I thought another option would appear. One did, but it was just a time trial option and used the same puzzles as I’d already done.
So, completed then! And it’s also logged as my 3rd most played 3DS game, just behind Ghost Recon and Street Fighter IV.