This file is DMCAed. Unfortunately the 'Can Download' feature is incorrect in this case, because it only checks if individual files are blocked, and in this case the block is inherited from a different level. Furthermore, that screenshot you posted shows a guest link, so even if the game wasn't DMCAed you wouldn't be able to download it because you're not logged in.
how to understand what games can be downloadable then ? same message appear even logged in btw , thanks for reply
Unfortunately if it's a Nintendo IP or on a Nintendo system it's more than likely DMCAed. Other than that, the 'can download' feature should be correct in most cases.