Yep.
It's basically an RPG where your choices affect the ending.
Kill everyone in the underground? Congrats you did the genocide run.
Kill everyone in the underground but didn't get the amount needed in the ruins therefore missing a few bosses? Congrats you got the neutral genocide run.
Spared everyone in the underground but didn't hang with undyne/didn't help Alphys get over herself? Congrats you got the neutral pacifist run.
Went back to fix some errors you made in the neutral pacifist run? Congrats you got the true pacifist run.
Killed a couple monsters and spared a couple monsters? Congrats you got the true neutral run.