This was a nice take on the theme. The critters were cute, and the customization was a nice feature.
It would be nice if you blocked placing on areas you have not unlocked, like you do for other conditions. I placed some in other areas and everything looked good as I ended the turn. Then I'd end up with fewer points than expected and the critters returned to be placed again. I experimented a bit with different placements before thinking to try buying the vouchers. Since I was not blocked from placing in all visible areas, I had assumed the new/unlocked areas would be shown when purchased, rather than being the areas you could already see and place into.