Detective Pikachu was released back in Japan back in 2016, and news on the localization of the sub-series has been quiet since then. Following the recent news that Ryan Reynolds will be cast as Detective Pikachu in the movie, Pokemon fansite Serebii found that Detective Pikachu was recently rated by the PEGI European ratings board.
The game was rated as PEGI 3, suitable for all age groups. Serebii notes that the release date shown is a placeholder date. The game is due for Nintendo 3DS.
Detective Pikachu is currently only available in Japan, for Nintendo 3DS.