1.The kids had a good / great time playing with the penguins.
2.The kids enjoyed themselves playing with the penguins.
3.The kids played with the penguins happily.(此句最为普通)
4.The kids were happy to play with the penguins.
我是江苏初中英语老师,有问题多交流,希望能对你有所帮助!祝进步!