Klonoa: Door to Phantomile was the tenth game directed by Hideo Yoshizawa, whose most famous works as a director were the Ninja Gaiden games on the NES.

Since Sony wanted no purely 2D games on the PlayStation 1, this title was something of a workaround: the environments are rendered in 3D, while the action takes place on a 2D plane. In video game terminology, this is referred to as 2.5D.

The hero, Klonoa has a hat that subtly features Namco’s most famous mascot with Pac-Man.

Klonoa, the character, is revealed not to be from the world of Phantomile but rather summoned there.

Originally, Klonoa was conceived as a character named Shady, who looked like a living shadow, but this prototype was cut from the final release.

Like Kirby, Klonoa appears happy and cheerful on the Japanese box art, but is portrayed as more serious on the American version.

There was once an idea to include a female rival or sidekick for Klonoa, but the concept was ultimately scrapped.