I posted this in the 3DS board and only three responses in six days, one of which is a misogynist, so I'm copying and pasting here:
Pushmo and Crashmo are mechanically different games. You cannot replicate a level from Pushmo to Crashmo, as it isn't everything the original is but more, like most sequels.
I prefer Pushmo. I think the puzzles are easier to visualize and give more flexibility for creation. You can make cohesive pieces, like the murals, whereas in Crashmo, only certain designs will work while still creating a challenge. I haven't gotten that far in Crashmo just yet, but I'm surprised to see that it has less levels than Pushmo. Even so, it still packs a lot of content. Also, I feel stupid rescuing Russian birds who don't care enough to fly away than innocent children who don't want to be there. Am I really saving them? Seems like they're just chilling.