Really fun, and I love the concept of playing with 3 different characters on the same level. Kept me interested enough to finish the game with all three.
The camera is a bit jarring when you get coins and jump.
It is unclear exactly what it takes to get killed (x number of bullets, or being somewhere in the vicinity of a stomper when he stomps). It took me many deaths before I figured out the stomper, which isn't always a bad thing, but I found it frustrating. When I die, I like to have an idea of what I could do differently next time.
The jumper is the hardest (imo) so its strange to put it first. I know that's kinda the default platformer mechanic, but I still feel that putting dasher first, or making the level more challenging for it might have been a better choice.