Dear Niveditha, Diwali is the festival celebrated to mark the victory of good over evil and light over darkness. This game is called "Thrash the Dark."
All you need is either candles or diyas with which you can light. Ask your employees in groups or individually to come forward and light a candle/diya and let the gathering know which dark quality in their life (personal/professional/social) they would like to overcome this Diwali... and you will see how much fun and commitment comes out of the game.
Wish you all the best.
Warm regards,
Ebenezar