Standing up together
There is no equipment required.
A small group is sitting on the floor, back to back. Then, the group has to try to stand up together without their arms touching the floor. Thus, the backs are pressed together and only the power of their legs helps to rise.
There are several variations possible: 2, 4, 6 or more people are in a team and by twos they sit back to back and hence form two rows. In another version, the people sit in a circle and link their arms. In a third alternative version, the people sit in a row, and every second person looks in another direction. There again, the arms are used to lean on the neighbors.