If you press X five times on the title screen, this menu will show up. Before you complete any endings, the menu displays “No Information”. Completing the Omega Flowey battle unlocks “Activity Level A”, going to the surface and getting the full end credits unlocks “Activity Level B”, and completing the intro for Sans’s boss fight unlocks “Activity Level C”. These can carry over even after a True Reset or selling your soul to Chara. For example, “Activity Level C” displays if the game is in “soulless mode”, and “Activity Level A” and “Activity Level B” both display if you’ve done a True Reset (although they get erased after Chara destroys the universe).

This is the only place where the game is affected by whether or not you’ve done a True Reset.