An activity I like to do for children that do not know any Spanish in the beginning of class is to start by teaching the phrase "Si te gusta" (If you like...) then show pictures of different activities while saying the Spanish verb (swimming, dance, biking, eating, skating, surfing, skiing, etc.) after showing the picture tell them a command (jump, stand on one foot, stick out your tongue, etc.)
The whole sequence goes:
I like this game because it can be as long or as short as you need it to be. It also teaches the imperative and the infinitive tense of verbs without really going into the complexity of grammar. Because of this it is fairly easy to follow if you don't speak the language. The verb cards can be interchangeable with the activity cards (since the words should not be written on the cards.) You could play with one pile of cards and make it a game "si te gusta... (pick card)...(pick card)"
Here are some verbs/activities you could use:
-Jump
-Biking
-Running
-Eating
-Skiing
-Horse back riding
-Laughing
-Dance
-Cook
-Learn
-Teach
-Sing