Just a bump, because Yoshizawa finally began to post stuff !
On summary as of August 5 : He explains that they started working on Klonoa in 1994, and after that talks about the 2D and 3D of this game, how the latter was attractive, and also about how it wasn't going to be easy to implement, although he ended his talk right at this point.
But I really recommend to use a quick Gl trad for this, even if the quality is not there. And also the other people's comments.
God damn Twitter is really weird to navigate through