I like the fox character, they've got a real cheeky grin!

The slightly top-down view is neat too, it allows you to put things inside the tiles as if they're item blocks. 

I think you could use some more subtle tile variations. In addition to the 4 rotated spirals, you could consider a cracked stone version or one with multiple smaller spirals. Perhaps even a couple double- or triple-wide tiles to help break things up. As it currently stands, the tiles feel very rigid to build interesting levels with.