I played AL-QADIM: THE GENIE'S CURSE years ago and i really enjoy it. And the game was in spanish.
Why the gog version hasnt spanish? I love play again this game in my own language, please add it. Thanks.
Because right issues (lot of local/regional localisations back in the day were done by different companies than orginal developers, usually local/regional publisher, and rights of those translations still remain with them (it they still exist)?
Other possibility is that GOG has no access to spanish localisized version either due to dev/publisher not having or unwilling to provide them (first one is more likely as lot GOG localizations were provided by GOGers who happened to own the localised version of the game and lot of times GOG has to aquire game files themselves as dev/publisher/rights owner not having them).
You could always ask them directly. Just don't expect quick answer.