NSFW content is only displayed if you have the option enabled
"Show content marked as adult in search & browse" under settings in your account.
In theory, children's accounts or if someone logs in without an account that has that option enabled, NO NSFW games should appear.
You can try using incognito mode in your browser.
PS: If you see an NSFW game without that option, it is because the game is mislabeled and it is best to report it so that the staff can make the adjustment or if not, notify the creator.