Formal:
* 祝你们玩得开心 (zhù nǐmen wán de kāixīn): This literally means "wish you play happily." This is the most formal and polite way to say it.
* 希望你们玩得愉快 (xīwàng nǐmen wán de yúkuài): This means "hope you play happily and comfortably." It is also quite formal.
Informal:
* 玩得开心 (wán de kāixīn): This means "play happily" and is a more informal way to say it.
* 好好玩 (hǎo hǎo wán): This means "have fun" and is very casual.
* 祝你们一切顺利 (zhù nǐmen yīqiè shùnlì): This means "wish you all the best" and can be used to wish someone good luck or a good time.
Which one to use depends on the situation:
* If you're speaking to elders or strangers, use the formal options.
* If you're speaking to friends or family, the informal options are fine.
You can also add a specific activity to make it more clear, such as:
* 祝你们旅行愉快 (zhù nǐmen lǚxíng yúkuài): Hope you have a pleasant trip.
* 希望你们吃饭愉快 (xīwàng nǐmen chīfàn yúkuài): Hope you enjoy your meal.
Remember that the best way to say "hope you enjoy yourselves" in Chinese is to use the phrase that is most appropriate for the situation.