Unpopular opinions, go!
Fun fact: Napstablook breaks the laws of physics. He's capable of faster than light movement, which he mentions in the epilogue of the True Pacifist route. Because Frisk is able to keep up with him and dodge/hit him, that means Frisk is also probably faster than light. Undertale humans are scary. Why are the monsters trying to escape to the surface? They're safer underground! If an untrained child can survive a huge drop into their kingdom and kill all of them with no formal training, what could trained soldiers do to them? Stay behind the barrier where you're safe!