You could arrange 1-minute games. Set up a time of half an hour/45 minutes and communicate the same to everyone. In that forum, you could organize 1-minute games, for example:
1) Who will drink the maximum water in 1 minute. Volunteers should step ahead... it's gonna be fun.
2) Ask questions like - who is wearing the maximum rings on his/her finger? That person should be rewarded.
3) Who is wearing red socks, etc.
Think of such ideas and implement them. It's not a very expensive affair. Rewards could be small fragranced candles, colorful diyas, etc.
You could also fix a dress code for the day. Tell people to wear bright colors - saree for gals and kurta pajama for guys, and then you could organize 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 the maximum recommendations would win.