@Sleepy sheep god ok. Lemme explain it. In nyakuza metro, when you are collecting 100 energy orbs, after you collect all of them don't grab the timepice but rather go to four different doors with red buttons next to them (one is in the end of minigame with collecting 15 of them, rest are one the 100 energy balls one). When you open all four doors one of them will open and you have to go inside there. You will be awarded with a secret level having wowza sticker in the end of it.
Secret boss:
Again, in nyakuza metro you need to go the way you go to green timepice: Get dirty, jump on cat roomba, then jump higher, higher, on little porkour area and than on a cat train. Just, instead of jumping to the timepice, jump to the place with snatcher coin. In the bright part of the green tower will be a very small gray wall. You need to walljump higher and higher using it and after that you will get on top of the tower. There it will have a terrarium with an egg and a spring somewhere in the darkness. When you jump on the spring you will be frown out of the ice hat vent or how are these thigs called. You need to come to this thing andinteract with it. If you do that, secret boss will jump out. He has 14 hp and doesn't give you anything when killed. He even pops like a usual enemy. I also recommend uing timestop hat
