英文翻译“尽情的玩耍”

楼上的专家应该知道这个说法吧？

to your heart's content？
它的意思是as much as you want:
比如：
a supervised play area where children can run around to their heart's content
（以上释义来自于OALD）

尽情玩耍： to enjoy yourself to your heart's content

Enjoy yourself to the fullest! 这是最适合的表达，老外就这么说

play as much as one likes

尽情 [简明汉英词典]
as much as one likes

have a nice time
enjoy oneself/it

最简单的说法：Have fun!