What are some sign language games for kids under 6?

-I am teaching a sign language to a group of 4, 6, and 7 year olds. They love to play "Mother May I", but I would like to introduce a new game. We played a relay game, but they just insisted that we play "Mother May I" again. I really need to find another game to play, any suggestions will be greatly apreciated.I would play like a memory game. Make cards with different words on them (some that the kids know and some that they don't) go over all the signs in the beginning and then set the cards face down either laid out or in a pile like go fish then a child turns over a card and signs the word on the card. The 4 year old might need help reading the word, but I think this would be really helpful in learning new signs and reviewing the old ones. I used sign language with my toddlers and it worked really well to let me know what they wanted and needed.
A fun one to do in a gym or something is act the animal. Have different pics of animals...horse, cat, fish, bird, monkey...and then each child picks one then acts I out. Then others guess the animal. Then you show them the sign for the animal. This also gets the kids used to gesturing out what they want o get across.
you could play "I Spy" with them or you could play "Hide and Seek."