Break the larger group into teams of 4-6 people. Give the teams ten minutes to come up with a one-minute (no longer!) skit which represents a movie that the leader (or a larger audience, if possible) must guess. When the time is up, have each group present their skit to the audience. For a twist, you can provide silly props that the teams are required to incorporate. Materials: props, if you want them.
Have the group sit in a circle. Have one person to volunteer to leave the room. This person is the "psychologist". While they are gone, the rest of the group needs to come up with a shared "problem" for the psychologist to diagnose. Possibilities include:
-Everyone thinks they are on the moon
-Everyone is afraid of the color the psychologist is wearing
-Everyone is thinks they are about to start their first day of kindergarten
-Everyone thinks they are late for something important
Once the "psychologist" comes back in, the players must act out the problem, being careful not to be too obvious. The "psychologist" gets three guesses to figure out the problem.
Five people are selected from the larger group. The leader writes one letter on each hand (totaling 10 hands), spelling the word SUMMERTIME. This group is then given two minutes to form as many words as possible by putting their hands in the correct order and showing them to the audience. To make the game more competitive, you could have two teams competing at once.