I got confirmation that GOG Subterrain includes Traditional Chinese even if the store page doesn't list it.

So far I counted three games whose store pages don't list languages that are actually in the game, the other two cases were Baldur's Gate III in Japanese and Succubus in Hungarian. We should gather other such examples and contact GOG once we have a good list.

I sent in a support ticket with a list of my outdated games.

Dawn of Man
Planetbase
World Racing 2 - Champion Edition
Tank Warfare: Tunisia 1943


Response from GOG. Hope this helps get the games updated.

Hello there. Thank you very much for reaching out to us and for sharing your concerns regarding the updates for your games on GOG.

Please rest assured that we’ve escalated this matter to the appropriate team internally, and we will do our best to have it addressed as soon as possible.

While we always aim to keep our catalog up to date, sometimes the timing of updates can depend on multiple factors, including developer-side decisions or technical differences between platform builds. That said, your feedback helps us identify where we need to improve, and it’s greatly appreciated.

Apologies for any inconvenience caused and if you have any other questions that you would like to ask, then feel free to reply to this e-mail and let me know.

Heh, canned reply. Let's see them actually do something about it...

Funny because last time I got a different reply. This a new default reply?

Well, don't know what the actual default is, if there is any, but I meant that it doesn't actually say anything specific, much less promise sorting things out quickly.

I guess the dev's plan to update it on GOG in the first half of April became the second half of May, but Contraption Maker finally got an update, to 1.4.35, so past the 1.4.33 that remains the last mentioned update elsewhere.