1. Watch the numbers on the door and notice that each time it changes, each number changes by 1.
The code depends on what number is shown at the top.
One way to beat it is to type 0276, then wait until you see the number 02764 at the top and then press the 4 button to finish the code.
Here are all the numbers:
2. Proceed to 100 Doors of Revenge Level 80!
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