A few days ago Nintendo snuck a Cadence of Hyrule: Crypt of the NecroDancer demo onto the Japanese eShop, leading folks to spring for their Japanese accounts and download it. But afterward it slowly trickled out into Europe, and now, America.
At $25 it can be a bit of a leap for some people (especially if you don't know how good the NecroDancer formula is), but now you can safely give it a try. The demo really should be all you need to test out whether or not the game will gel with your tastes, but just know that it's the type of thing you'll want to replay over and over as time goes on.
Seriously, this level of collaboration between Nintendo and an indie studio isn't a daily occurrence, so it's worth at least supporting with a demo play if you aren't game to throw down on it. Hopefully it'll lead to a more relaxed use of Nintendo's IP with trusted studios.