My suggestion is an alternate version of EggWars with the following changes:
- All players are on a single team together
- The goal is no longer to defeat the other teams, but to survive as many waves as you can together, similar to Hypixel Zombies
- One other team base (preferably the one directly across from the player team's base) is designated as the enemy hive, where hostile mobs are spawned
- Scripted endermen (like the bridge-builder endermen in BedWars) build defenses for the enemy hive and pathways for the other mobs to invade