Yes

The stuff about ghosting probably refers to the ghost console command, which is Unreal's equivalent to noclip in Source games. It's not needed at least for the boss fight though, although I'm pretty sure it is needed for the second part (assuming you don't use mods like the Kirby Hat or Infinite Jump Badge)

I don't understand "ghost" but for everyone wondering, it is possible to make it on top of the green walls no mods or hacks. When you are up there, there is a small cage with an egg inside (hat kid says egg when you click on it) and on the roof of where you got the Green Clean time piece is a platter of Jell-O. (I also found one in a window-forgot where) There is a trampoline that leads you to a platform high above the metro (awesome views). When you click on the manhole cover, a cat with an eyepatch pops out and screams HAT KID-CHAAAAAAN!. Then you fight him.

What does "ghost over into this corner" mean?

yeehaw :)

Dev console

Instructions unclear. Can't understand what 'ghost towards' means.

Yeehaw :)

i guess i could add that

There's a spring right next to the egg, which takes you to a manhole waaay above the rest of the Metro. If you interact with the manhole you get the message "Huh there's something written on this manhole" followed by the message "Kiwami means extreme." A cat wearing an eyepatch will jump out of the manhole and yelling "HAT KID-CHAAAAN!" before announcing "You've grown soft, time to bring out your fighting spirit!" he will engage you, and you must fight him to the death. Successfully beating him brings you back to the start of the Metro.