Best budget game for Nintendo Switch?

I recently got a Nintendo Switch, and I am looking to expand my library. Does anyone have any suggestions? There is only one parameter I request that you work with: it should be $30 or less. It could be a game that is out now, or one that will arrive on the eShop in the near future. Thanks for all of the suggestions!

*Image courtesy of http://www.nintendo.com/switch/buy-now/#nintendo-switch-gray