I got really turned off when it was listed as "Free (with in-app purchases)". Turns out it's basically a 10 minute demo, after which you have to pay $9.99. Maybe it's good, but deceptive enough I uninstalled it.
Personally, I find the 'free demo' model far preferable to the two alternatives, upfront payment and microtransaction hell. The former is problematic on iOS where there are no refunds (more or less; at least, Apple's refund process is cumbersome with no guarantee of acceptance) - I've purchased countless apps for a few dollars (after looking at the description and screenshots) just to realize, literally seconds after…
Maybe it's buried in the description somewhere, but the first indication I got that it was a demo was after wasting about 25 minutes downloading, installing, setting up a Nintendo account, downloading more levels, then learning the game mechanics.