These codes can only be entered after doing the easter egg.

Hover over "Start Match" in Custom Game or Solo Match OR Hover over "Loadout" in Public Match.

What it means by enter a "code" you must enter the following movements with your Controller D-Pad or with Keyboard Arrow Keys.

You must be quick with entering these codes.

Only for Zombies in Spaceland

Enter this code:

Left Right Left Up Down
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← → ← ↑ ↓

Only for Rave in the Redwoods

Enter this code:

Right Left Left Down Down Right
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→ ← ← ↓ ↓ →

Only for Shaolin Shuffle

Enter this code:

Up Up Right Left Down Left
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↑ ↑ → ← ↓ ←

Only for Attack of the Radioactive Thing

Enter this code:

Down Right Down Left Up Right
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↓ → ↓ ← ↑ →

Only for Zombies in Spaceland

(Complete all Easter Eggs including DLC 4 and be on Director's Cut)

Enter this code:

Left Left Down Up Up Right
-------------------------------------
← ← ↓ ↑ ↑ →