You could arrange 1 minute games. Set up a time of half an hour/45 minutes...communicate the same to everyone. In that forum you could organise 1 minute games, for eg-
1) Who will drink maximum water in 1 minute. Volunteers should step ahead...it's gonna be fun
2) Ask questions like- who is wearing maximam rings in his/her finger??? That person should be rewarded.
3) Who is wearing red socks etc etc
Think of such ideas and implement them. It's not a very expensive affair. Rewards could be small fragrented candles, colourful diyas etc
You could also fix a dress code for the day. Tell people to wear bright colours- saree for gals and kurta paijama for guys and then you could organise a Miss Phuljhadi and Mr. Patakha contest. Ask everyone to nominate those people who are looking the best. Collect the chits and start counting. The person with maximum recommendation would win.