Nintendo wasn’t even trying, it was all their old sprite characters from Japan market that didn’t do well smashed together in a rushed title for an NA launch. It surprised them.
https://grantland.com/features/the-rise-of-nintendo-video-ga...
https://iwataasks.nintendo.com/interviews/wii/mario25th/4/0/
https://www.reddit.com/r/AskHistorians/comments/2w1zl4/when_...