Have students spread out in the playing area in their own self space. The object is to hit as many feet as possible during the time limit. After throwing the ball the students retrieve the ball, return to the playing area, and continue playing trying to hit as many different classmates feet as possible. Students may avoid someone else's ball from hitting their feet by jumping, sliding, etc.
Older students can use the overhand throwing motion.
Have students throw with their non-dominant hand. This makes for a good conversation after the activity is over. Take resting pulse before and after activity to see how this activity raises heart rate. Students have a tendency to run after stray balls with their head down. Make sure your students have a good grasp on moving in general space with others in a dynamic setting.