Great choice! Monkey Island 1 (The Secret of Monkey Island) uses the SCUMM engine (v5) and has well-established tooling. The Talkie CD version adds voice acting, which you'd keep while translating text. Overview You'll need to:
- Extract text strings from game data
- Translate to Vietnamese
- Create/modify fonts to support Vietnamese characters
- Repack the game data
- Test with ScummVM Tools You'll Need | Tool | Purpose |