I would under most circumstances agree with the sequel non-rewarding, but Crashmo is not only the successor to a new IP, but changes so fundamentally the gameplay mechanics of Pushmo that, I believe, it deserves to be rewarded especially as such, because it's a damn impressive feat they've pulled off.
Not only that, but it fixes many of the common complaints with Pushmo such as the overlong, unskippable tutorial, gradual unlocking of key features, and repetitive music without much variety.
Crashmo, you guys!