Quality not withstanding you’ve got to pay for access to the model or electricity to run your own local model, pay people to run the lines into the model and stitch them back into the game and pay people who speak the language to proof read the outputs to ensure it’s not giving you gibberish.
And if you’ve got voice lines now that’s a whole other can of worms of paying for TTS ai models, paying for audio mixing specialists, inserting the lines into the game, paying to once again have a speaker of the language QA test the output.