Level 5 president and CEO, Akihiro Hino, has explained to Wired why it takes so long for Professor Layton games to make it outside of Japan.
Not only do puzzle differences with Japanese linguistics or customs need to be substituted, but some graphical elements need a bit of tweaking as well.
“Like any game localization, it takes time and manpower to update a Professor Layton title, especially the puzzles and any graphical elements that need adjustment,” said Hino. “We all try to carefully manage this process so that there is not such a long gap between releases.
“Of course, we also want to let each title have time to perform on the market before releasing the next game.
There ya go.