We had a mobile casino as well as a DJ. The guests were given play money on entry, and we had Blackjack and Roulette.
It worked really well, and two couples in our friend group did exactly the same when they got married within 3 years of us, as they'd loved it so much.
One couple even used the same company as they live locally, and the croupier on the Blackjack table was the same one as at mine (weddings were 11 months apart). That wedding also had a salsa band to kick the night off after dinner. They did a performance, and then guests were invited to have a go. That was brilliant fun! They later had a DJ, too.
The most boring wedding we ever went to was 6 weeks after ours and had the ceremony at 12pm and food at 5pm. Between 1 and 5 was a 'drinks reception' on the lawn of the hotel. No food. No music. No entertainment. But arguably a nice venue and good conversation. It was a very long day. Many people got drunk as there was nothing to do, and as the ceremony had taken place over lunch, no one had eaten since breakfast. It was the middle of nowhere too, so we couldn't even leave to get food!
They had a DJ from 8 pm, but the bride had been specific in the style of music she wanted him to play, and he wasn't allowed to deviate from that, so requests were turned down. The result was an empty dancefloor with people leaving to go to bed at 10 pm. DH disappeared back to our room to watch MOTD.
80 people is a lot. A good venue and good company are enough if you're having an intimate dinner. 80 guests is a party. You say there are little ones coming. What are you expecting them to do? They'll be running around. Good food and conversation aren't for them. They need music and space to run/spin/dance.
All weddings mentioned had between 80 and 100 guests for the evening.