IGN gave it a 9.5/10! I'll download it as soon as I buy the appropriate card.
"Nintendo's at last brought us an exclusive download-only eShop title that is an absolute must-have game... this may very well be the best downloadable game Nintendo's ever offered in any format... Buy it. Love it. And get to work making some of your very own Pushmo, because I want to play them."
http://ds.ign.com/objects/119/119061.html