To trigger the easter egg cutscene survive to round 150.
Recommend Class Set Up:
Talismans/Elixirs (If you have them available) -
Frugal Fetish - Reduces cost of the shield. Shield repairs greatly increase in cost as rounds increase. Points will become scarce, this talisman reduces the impact of that cost
Equipmint - Resupply wraith fire grendes
Arsenal Accelerator - Regenerates specialist weapon more quickly
Temporal Gift - Extends duration of Double Points and Instakill
Power Keg - Instantly replenishes the specialist weapon
Perks -
Time Slip (Modifier Position) - Rapidly speeds up recharge of weapons.
Stone Cold Stronghold - Can take 2 additional hits when armor is built up and damage within the circle is increased
Victorious Tortoise - When the shield is broken it will knock back all zombies
Dying Wish - In case you take too manu hits, this perk will allow you to recover without taking a down
Weapons -
Ragnarok DG-5
Wraith Fire -
Starting Weapon - This doesn't really matter. Strife with the operator mod is good for early point building.
Strategy -
Build Shield in the Weapon Testing Room
Train zombies in the War Room: Lower Level until Round 50
Use the ICR Wall Buy and Winter Howl
Stop training when you have built up approximately 300,000 points
Go to the Weapon Testing room on the lowest level of the map
To the left of the work bench there is a pool of blood. Stand in the pool and allow your Stone Cold Stronghold to activate
Back yourself into the corner to the left of the workbench
Get as many headshots as you can with the shields gun
Once the shield comes close to breaking, turn to your left and repair it
If your shield does break Victorious Tortoise will knock back the Zombies
At this time spam your upgraded Winter's Howl and purchase a ew shield
Periodically place down Rags and Wraith Fire Grenages (Use them when you have them)
TAKE BREAKS - This strategy is intense and may take you a few attempts to get it right. I would recommend practicing in Custom Game
Survive to round 150 and the cutscene will trigger. The game does not end so if you want to go for a higher round return to weapon testing.