"Undertale": Gameplay Trivia Quiz

Answer: Flowey

In the introduction, Chara is mentioned as the "Fallen Human" though is never properly introduced by the game or them. Flowey is the first character that greets you and then tries to kill you.

Answer: Six

You must cross the Ruins, Snowdin, Waterfall, Hotlands, the Core, and the Capital until you can confront the king himself. Though the underground may be more expanse than that, the player explores only these areas due to the limitations of pathways and storywise. The main setting, however, is Mt. Ebott.

Answer: Mettaton

He confronts you, saying that he'll kill you and use your SOUL to go through the barrier and up to the surface and show himself to the humans if you are playing the True Pacifist run. If you play the Genocide Run, he'll transform into Mettaton NEO, but will ultimately be defeated in one blow.

Answer: Spear of Justice

"Battle Against A True Hero", plays on the Genocide Run of her fight, while "Bonetrusle" appears in Papyrus's fight, and "It's Raining Somewhere Else" for when you go on a second "break" with Sans. Her fight also changes with each run, more of an easy-going with the Neutral and Pacifist, but hardcore and difficult with the Genocide Runners. Either route uses Shield Mode, or the Green SOUL's way to defend itself, though you can not escape the Genocide Run when you turn into a red SOUL.

Answer: The Echo Flower

Sans also goes on to say that the flower says good things, hints, and premonitions to Papyrus when he hears them. It may be Flowey talking to these flowers and making them repeat it, so that Papyrus hears it without Flowey appearing before him. It could also be Flowey directly talking to Papyrus.

Answer: Level of Violence and Execution Points

Sans explain this to the player in the Judgement Hall before the Throne Room while judging the player for their actions. It puts a new twist on RPG statistics when you think about it.

Answer: Papyrus

In the name selection screen, the six character limit only makes the name as Papyru. But the text "I'LL ALLOW IT!" replaces the old text, "Is this name correct?" How is this Papyrus? He's the only character where his text is in capitals. Anyways, naming other characters allows different responses but some of them aren't allowed to use in-game, such as Sans (nope) and Undyne (Get your OWN name!).

Answer: The easiest enemy. Can only deal 1 damage.

Sans's fight is known to be the hardest fight in the game and is only accessible through the Genocide Run. He dodges every attack and can kill you in a matter of seconds due to his poison effect named Karma, which is actually a force that determines your future based on your actions.

Answer: Stick

Throwing the stick will make almost every dog happy in real life, and so does in the game itself. However, other characters will also have responses when used with the stick, such as Mettaton EX catching it with his mouth and winking, which raises the ratings and Papyrus would fetch it.

Answer: 90 HP

There's a certain mode called "Serious Mode" activated during Boss Monster fights (Toriel, Asgore, and Asriel). They shorten the comical names of items and skip the time-wasting text of the Instant Noodles and increase the regeneration of health from 4 to 90.

Other than that, other bosses have comical items and it's not known why it affects these three monsters, since other bosses are fighting for serious reasons as well.