As part of the Virtual Console 30th Anniversary promotion on the Wii U, Kirby's Adventure is $0.30 until May 16th. Although this classic NES title is available pretty much everywhere under the sun, including Kirby's Dream Collection and the 3DS eShop, you really can't go wrong with that pricepoint, especially given the fact that it's playable with remote play.
The full-on Wii U Virtual Console update is expected in the next day or so, which will come with vastly improved system load times, as well as a number of other Wii U Virtual console games. After the Kirby offer is over, Super Metroid will be available from May 15th until June 13th. Mark your calendars!