hey guys just asking I forgot what mode it is when you go up to the surface with all of the monsters? I forgot and I want a happy ending

No mercy route.
I'm kidding, you have to do the True Pacifist or Pacifist Route.

Sorry but i didnt know Undertale i try to have the game. Or i licten youtuber play it for know.

Pasafist

Don't kill anything and go on a date with papyrus (or hang out), make friends with Undyne, Hang out with Alphys and discover her dark secret and deliver a letter to Alphys from Undyne. This will get you to the pacifist ending, I hope this helped!

Don't kill anything, even Papyrus or Sans will kill you.

ty guys really helped

you mean the pacifist path?