This is so incredibly adorable and cute, I'm hooked and I'm a guy. How do I unlock the other Region? I leveled up 3 Nimikins and prestiged twice, and collected all 7 types.
I was confused a bit at first because I couldn't make the shop screen go away, I didn't realize you had to click the shop button, maybe you might want to add an "X" on the screens so you can go back to the crystal land. Maybe add a few tutorial screens just letting the user know to "equip a Nimikins in the bottom right corner" etc...
I'd love for you two to expand this concept more. Give the Nimikins more to do, more to work on. Maybe have 3 slots for Nimikins to mine crystals, and 3 slots to make Nimikins to rebuild a castle or something to work towards.
My Fav Nimikins are the Blush Frog, and the Salty Crab.