The crevice is definitely a cool addition. I like the way you reused that single room for a bidirectional passage by warping the player to the top or bottom of the crevice adjacent to the exit for the direction they're headed.
I think it doesn't end? You collect the faffins and then you're stuck?
The pink and purple look great together. The bit about "you can't go to the city" is a cool way of indicating there's more to the wider world that you can't access.