Sort of interesting?
The game does have an appropriate "dream like" feel. I suppose the "babies dream of dead worlds" thing implies this is supposed to be some sort of recollection of past life, or something like that. But this is pointless if it's limited to being just something you hint at in a cryptic phrase on the level-select screen.
That leads me to the biggest problem with the game, which is that it just seems... pointless. You've made a game about a baby's dream. Okay. But then you completely miss what's actually so interesting about that idea. It's not the dream itself, it's the fact that it's a baby having it. Why is the baby having this dream? What are these characters? ARE they people from a past life, or are they figments of the baby's imagination? You didn't touch on that at all, which made the game just feel without purpose. You can pat yourself on the back that you got across the fact that this was another world very efficiently (I didn't even read the author comments until after playing, and I still got it), but that efficiency is matched by the shallowness of it.
I like the idea that this is a glimpse into some strange, hidden universe that the baby is remembering in the form of a dream. It's mysterious, disquieting, and compelling. It's great that you managed to bring across that slight alien creepiness through not only music and visuals, but gameplay (with a completely alien form of control and gravity) as well. Nice one. It's also rounded off by the disjointed, non-linear structure of the narrative, which I think adds to the mystery and the incoherent dream-like feel.
...but, it is POINTLESS when it's just left in isolation like that. What is interesting about this world is that it is a baby's dream. But other than the game's title and very brief opening cutscene are the only things that tell us that. You need in some way to link the baby's world with the dream -- maybe splice in gameplay segments where the baby wake up momentarily, I don't know.
Anyway, technical aspects.
Music got the job done even if it wasn't completely stellar, control scheme was interesting and intuitive once you grasped the concept that gravity always tugged you towards the middle of the level. And as I said, it also added to the alien feel of the game's universe.
However, the level design was generally very poor. The racing and coin-collecting challenges were just pointless (not to mention boring to play anyway). The visuals were also probably out of place. You realize not all artsy games have to be done in retro pixellated graphics, right? In this case I really feel something easier on the eyes would have been preferable. I understand that retro graphics comes as much (if not more) from poor artistic skills on the part of the author as it does from artistic choice, but if that's the case surely you must know SOMEONE with better spriting skills that you can collaborate with.