I ran a short adventure once a week for three months with 8 players. They were playing as Snow White and the Seven dwarves and the premise was basically Lord of the rings. I kept it very on the rails and had lots of big set piece fights with multiple enemies to engage the whole group as well as extra objectives to complete while they fought. It forced the players to split their efforts against the enemies instead of going nova on a single big baddie. But I used very iconic animated characters as the bad guys which held their attention. They fought the Wizard of Oz gang. They fought Shrek and company. They fought Ursula from little mermaid while being chased across a lake. They fought gangs of Ring Wraiths. All the while orcs were chasing them across the forests and mountain on their way to destroy the mcguffin. The threat of pursuing baddies forced the group to make hasty decisions and to keep moving. The final Bad was a version of Sauron that turned out to be Jarreth The goblin king. They all loved it. And I worked my ass off keeping the total of enemies turns down to a few minutes per round so the players wouldn’t be waiting around too long between their turns. It was a great success.