I learned this game from students in an English class at Meiji University.
In this game participants add words to make a sentence under pressure of time.
Part One:
Everyone stands in a circle.
One person starts a sentence by saying one word. The next person has five seconds to add a word that continues the sentence, and so on until someone fails to add a word, or adds a word that doesn't work. When that happens -- the group screams, or makes an explosion sound, etc.
Example:
1. My
2. mother
3. was
4. born
5. in
6. a
7. ........ [time's up: everyone, "Boom!" -- (or a big cheer to celebrate the mistake)]
Part Two:
Form [three] teams of three to six people.
Team 1 will be the time keepers and judges. Teams 2 and 3 will compete.
The teams compete head to head, each team simultaneously writing a [ten word] sentence on the blackboard, one player - one word, with a five second time limit. The team that misses the time limit loses. If both reach [ten] words, the judges check the sentences for errors and choose the winner -- the sentence with the fewest errors.
In the next round, the winning Team become time keepers/judges, and Team 1 competes. Rotate each round.
You can increase the number of words each round.
You can also make it more challenging (and/or thematic) by giving the teams a set of words their sentences must include.
Example: "Your 15 word sentence must include the words: Greece, election, hot, pancake"
"The election in Greece, where the economy is flat as a pancake, was too hot."