If you want to know a cheat-cheat just get the pixl that allows you to turn sideways-ish.
In the mansion after you have broken the vase and stuff you can go to the second floor and turn to peach and jump over to the other side making you float after that go to Mario and flip dimensions and follow the arrow on the ground until you get to the chest, when you press up you will meet the pixl named slim. After this go to the third floor and go flip dimensions when you get to the wall and then hit the brick which will make a ladder appear. Climb up the ladder to get to the top and use slim to get past the beam. After you get past the beam there should be a big safe the code is: 41262816. thanks for reading