Japanese users of My Nintendo, the new Nintendo initiative to replace the now defunct Club Nintendo, will be able to download Warioware Touch as a reward for the amount of 1000 points on all models of Nintendo 3DS.
An amount of 214 blocks (24MB) is required. You can also see other rewards here.
Originally released in 2005, Warioware Touch on the Nintendo DS has a Metacritic score of 81, with websites such as Gamesradar giving it a perfect score.
The download is a recompiled DSi game, this was probably done by Nintendo in order to avoid hackers injecting Nintendo DS roms in Virtual Console files.
