This is a bug that still works (will delete once fixed) where if you are in an open area, have at least 3 boxes (or other items, but I prefer boxes) you can reach the top of the map, go to areas you couldn't before, and show off to your friends (easiness of the bug depends on your internet!).
Guide to Flying with Boxes (Step-by-Step)
Find 3 boxes.
Place one of the boxes in an open area (where you want to go directly up).
Fill your inventory slots with boxes.
Jump onto the box you placed earlier, and look down at it.
Now the flying part. The logic behind the bug is that, in Secret Neighbor, if your inventory is full and you pick up an item, it replaces the item you are currently holding with the item you picked up, and drops the item you where holding underneath you, if you are in midair. This way, you can rather easily jump, replace, stand on, jump, replace, stand on, and you will go higher and higher (the more practice, the better). Watch the video for a demonstration on how to get to the roof easily.