All you need to know about
Nuclear Submarine old dev build

Roblox puts in extra effort to ensure a safe space where players of all ages can freely create, play, learn, and imagine.
Roblox also groups games into four age-based categories to indicate appropriateness: All Ages, 9+, 13+, and 17+.

You can find Nuclear Submarine old dev build’s age rating here.

For additional parental controls, go to Settings (gear icon) and Parental Control at https://corp.roblox.com/safety-civility-resources/?section=Families&article=customizable-parental-controls