if each disc is from a different game, you could probably use the medium title field, especially if it’s clear in the liner notes and whatnot. there’s a similar example from an anime here.
if each disc has music from multiple games, there’s another thread with a similar issue (and a ticket to maybe solve the problem):
a possible solution would be to use something like the recording disambiguation (probably good to have this data there anyways). if you need that information in your tags, you could probably put together a Picard taggerscript to include the disambiguation in the track title too. that wouldn’t show up on the release page however, but that could also be put in the release annotation if needed?