Biggest Sleeper Hits of All Time

[Bofferbrauer2]

Splatoon on Wii U. Went from "will sell like The Wonderful 101" to THE bestselling game on the platform in Japan, a coiuntry which until then was generally averse of first- and third person shooters of any kind.

Undertale also counts. It just barely made it's very modest goal on Kickstarter when the platform was still pretty unknown and ha a very silent release, but went on to become a juggernaut of the internet and in terms of sales.

As unbelievable as it may sound nowadays, Mortal Kombat and Super Smash Bros count in a way. Mortal Kombat was just developed to fill up a gap in Midway's arcade lineup for that year and with minimal funds, but did so well in arcades that when it came to consoles, it was a big hit already. Smash bros was developed in the spare time of Sakurai and his team at HAL and wasn't intended to become something big (fighting games where really not selling well at the time), heck it wasn't even supposed to get a western release. But it finally did so well it got a western release, where it did very well too. It's also the reason why the cast is so limited in both games, 7(+1) and 8(+4) was very limited already at their respective release dates