1 What are Frisk's and Chara's genders actually supposed to be?
Probably Apache attack helicopter.
2 Which dog is best dog?
3 Could the Alphys X Amalgamates shipping actually be canon?
4 Is Alphys really as weak as she lets on, or is there actually some degree of truth behind the Alphys NEO fight?
5 Did Gaster intentionally base Sans and Papyrus off of Mario and Luigi, or was it just a very fortunate coincidence?
6 Is Alphys really a girl, or is she actually just an incredibly effeminate transgender boy?
7 Which flamboyant male pop star was Mettaton EX's design REALLY based off of? (Or was it actually an anime character all along?)
8 Can Papyrus actually go "super" like how Sans does in the Genocide Run?
9 Is Chara truly evil in the first place, or just misunderstood?
10 How does Frisk see with his eyes perpetually closed?
The Contenders
11 How hard of a boss fight could Mettaton NEO have canonically been if Alphys had only taken the time to work on his defensive capabilities?
12 Where (or who) did Papyrus REALLY get his spaghetti obsession from?
13 Were Sans and Papyrus born naturally, or were they merely scientifically created by Gaster's experiments?
14 Who left the Abandoned Quiche underneath the bench in Waterfall?
15 Where exactly did Alphys get the idea to name Lemon Bread LEMON BREAD?
For once, you are right.
16 What was the exact cause of Gaster's death?
By setting your 'fun' to certain levels, grey NPCS will appear. they say that Gaster shattered across time and space, or fell into his own creation. Gaster created the core so maybe he could be inside the core...? Gaster also typed in Entry 16 in the true lab saying
DARKER DARKER YET DARKER
THIS EXPERIMENT LOOKS
VERY VERY INTERESTING.
WHAT DO YOU TWO THINK?
You two? Could this be possibly referring to Sans and Papyrus? Toriel and Asgore? Chara and another human? Whatever, Gaster is possibly the most mysterious character in the whole of the game.
17 Is there really any limit to how far Lesser Dog's neck can be stretched?
18 How did Flowey come up with the design for his Omega/Photoshop form?
19 Why do Asgore and Toriel both have literally the exact same house as each other?
Becasue they originally live at the ruins, but then they both moved to new home, where they wanted the same house layout so they wouldn't be nostalgia
20 Why isn't the Alphys NEO fight in the actual game?
21 Is the giantess scene from Alphys VS Undyne actually fully possible with Alphys' canonical anatomy?
22 Is there anything that Sans truly loves more than ketchup and bad puns?
23 What are Snowdrake's parents' real names?
24 If Lemon Bread is Shyren's sister, then who is Shyren's brother? (Aaron?)
25 How exactly are the Memoryheads linked to Gaster?