https://wccftech.com/astral-chain-final-file-size/

Astral Chain is releasing in around two months worldwide, but starting today, those who pre-ordered the game on the Japanese eShop can start preloading it on their console. Preload starting also means that we now know the game’s final file size.

Astral Chain won’t be among the biggest Nintendo Switch release, as it will require 9.6 GB of storage space. The Japanese version includes all of the language options that will be available in the Western release, so the file size is not going to be much different.