The Easter Egg for this map is prety much easy, but if you're struggling with it, here are the steps:

Be sure that you have subtitles enabled in the audio menu


-Talk to the guy inside the Bank, he will ask you to fill some soulboxes around the map.



-there is a total of 5 soulboxes around the map in the form of cats.







-After this a door will open inside the laboratory and you will need to get the first Keycard there.


-After getting the first Keycard, got talk to the guy again, he will tell you to open a locked tunnel, you will need to find 4 keys to do this.






-When you get the keys, go open the door and get the second Keycard.


-Go talk to the guy again, he will give you the instructions to the third Keycard

-You'll need to explode 3 big clocks around the town and activate 3 tiny ones, you can buy an rpg-7 on the side of the mule-kick or you can use grenades do explode the big ones, it will work even with widow's wine

Those are the big ones you'll need to destroy:





Those are the tiny ones you'll need to activate:

-One is inside the pack-a-punch room.



-The other is inside the DISCO area, on the second floor.



-The last one is inside the bar upper bridge.



Doing this will unlock a door on the right side of the pack-a-punch room, this will gave you the hability to change the skybox and access to the third Keycard.


-Talk to the guy again, he will gave you the instructions to the fourth keycard

-The crystal the guy is talking about is floating on the same area as the madgaz moonshine perk



-Use the trap on the bridge to launch you in the air so you can grab the crystal



-After this, keep following the crystal and grabbing them, until it gets inside de laboratory, then a case with the fourth Keycard inside should open for you to grab it. The elemental Bows also will be available to buy


-To get the fifth keycard, you only need to talk to the guy inside the bank, he will gave you the last keycard.




Put all the five Keycards on a table inside the laboratory, this will unlock the special Wonder Weapon and the escape door to be bought in the back of the lab.





Buy the escape door for 45K, activate the evacuation system, go to the upper bridge and get inside the truck to escape.