Starmen.Net

• Apparently if you save some spider food from the bake sale in the ruins, and eat it during the Ms. Muffet fight, you can get some interesting results.

• If you’re going for a Genocide run, or just want to get lots of enemy encounters, you can alt-tab out of the game when in windowed mode and your character will continue to walk in place, advancing the step counter until the next monster encounter.

• Sans’s word search puzzle is actually unsolvable. The line of gibberish letters is spelt differently in the first row, by just one letter.

• Mettaton’s maze is actually solvable, resulting in a few more lines of dialogue between him and Alphys

Before finishing the perfect pacifist, try talking to everyone more than once, and also try calling Toriel’s phone! She’ll send you a new message every time you enter a new room, so you can keep walking back and forth between The End and the Throne Room to read them all. They’re super cute!!!

^ Seconding this, he’ll tell you he won’t give you yellow names and if you agree to this, you do indeed get yellow names taken away. You don’t get to know when you can spare an enemy anymore for the rest of the playthrough!

^ I HAVE TO TRY THAT NOW oh my gosh

MariettaRC:

• You can use the Stick you start off with as an item against dogs. It makes them instantly sparable! IT WORKS ON PAPYRUS TOO. Though not as a sparing action.

Noting this as an experiment for my next Pacifist run: See if this works on the Amalgamate.

Also I’d like to add that you can use the stick to play fetch with Mettaton EX too! It’s beautiful and gives you great ratings!

Granja:

Oh damn. Didn’t think about saving the butterscotch-cinnamon pie for the Asgore fight.

I kept it through my first playthrough because I understood it as a unique item, since Toriel asks what flavour you like and especially bakes it for you. And when I got the idea to use it in the fight with Asgore, I thought that's the solution. Talking to him, using the pie... feeling like I missed another key item

MariettaRC:

Noting this as an experiment for my next Pacifist run: See if this works on the Amalgamate.

it works on the dog amalgate, the one you find infront of the fans. It also works on Mettaton and gives you a fair amount of ratings

^ There’s other names that’ll give you different results, too. Put in “Toriel” and she’ll admonish you to “choose another name, child.” You can probably think of a few others that fit.

MariettaRC:

• For the love of God and all that is merciful, pet Lesser Dog more than once. It’s glorious and it doesn’t end.

The first step is admitting that you have a problem.

(Also, the amount of pets you give Lesser Dog changes the snowdog room.)

For some fun, try naming your file something that shows you’re aware of the True Pacifist ending.

You know, Frisk.

To add to this, try naming your file after various NPCS. Examples: major characters like Toriel, down to various encounters like Woshua and Aaron. And a certain Gaster. (EDIT: Oops, beaten by two others!)

The names Chara, Mercy, and Murder will also elicit reactions.

Try walking back to the left after locating the human SOUL substitute. Pay close attention; it’ll only show up for a couple of frames. You may even want to load your save to see a second time, but when you’re expecting it, I think you’ll know what you saw.

Stay still for a long time during Madjick's Chaser attack (not the one where a single chaser spawns stationary crosses) Do not move even after the activation. You may have to wait a while to get any benefit.

There’s a couple times in this game where standing completely still/not doing anything gives you some fun extra dialogue

-People have already brought this up, but if you stay completely still during a couple boss fights (I know for sure for Papyrus and Undyne), they’ll have some unique dialogue for you. Just be ready to take damage!

-During Mettaton’s puzzle, where you have to walk across the colored tiles, try not stepping on a single tile/just standing completely still. Usually, his dialogue says something about how you stepped on a green tile, so the monster you have to fight is him. But if you don’t step on anything, he gets a bit stumped.He fights you anyway, obviously

-Something similar happens if you do the same thing during that jetpack section, too, I think. Or maybe that’s just if you fail it. I dunno.

-During the Mettaton fight, when Alphys calls and tells you to press the yellow button in your Act menu to activate the jetpack, don’t. Delay it a bit and there’s some extra dialogue.

-When you date Papyrus, he tells you to press a button to activate the Dating Hud or whatever that thing is. Don’t press anything, and he says some extra stuff.

I’m sure there’s more!

Here’s a not-so-fun trick: After killing Toriel on a genocide run, go back to the house and examine the counter!

iirc, the telegram from the spiders in the Ruins still happens, only it says you didn’t hurt any spiders

The recommended way to buy Muffet’s food is to abuse the Dog Residue item for infinite money at temmie village.

It takes a heck of a long time though

In addition, regarding Muffet, eating a Spider Donut or drinking a Spider Cider during the battle will cause the telegram to arrive that very turn, which means that you are able to end the fight as early as the first turn as long as you kept the item from the Ruins.

Boots:

• Mettaton’s maze is actually solvable, resulting in a few more lines of dialogue between him and Alphys

Maze Solution

hide spoiler

Image credit from Artemis251

Maaaaan you stole my thunder

• Save your game near the end of the game right before Sans judges you. After he has, reload and repeat a few times. He’ll eventually give you the key to his room.

• If you’re wondering what the locked shack is next to Papyrus’s house, lose to him on purpose in your fight with him.

• Walk around a TON in the weird pre-Snowdin room that has 4 mushrooms and a locked door. There’s a secret fight there, but it only shows up if you haven’t gotten far enough in the game to have enemies standing on the map as NPCs. Also, keep in mind it takes like 5 minutes of walking. It may be best to do that trick where you click outside the game window so your character keeps walking.

• Additionally, there’s a hidden fight in Hotland on the screen above the place you get the Apron. I’m not sure exactly what triggers it, but I think it’s a fight on the screen. Try walking against the north limit to find a magic-tile bridge north.

Also I feel compelled to share that I actually solved Mettaton’s train math problem back when I was beta testing. Originally all 4 answers were wrong, so I gave Toby the right one. He laughed and said he was waiting for someone to actually do the problem for him so he didn’t have to. (I can’t tell if I won or lost that one)

…Hm. That actually does bring up an interesting question.

Not sure if this is intentional or a glitch. This happened during my genocide run, but it might happen in any run (needs confirmation).

In the place where you “meet” Undyne for the first time: you’ll stop in the tall grass, noticing Undyne’s presence. Instead of advancing further, take a step back toward the entrance. Undyne will try to find you as usual, but…

Oh okay, thanks.

PIGRSI:

By the way, I know Muffet will spare you if you buy a spider item earlier, but does she still spare you if you didn’t?

Yes, she gets a message saying that you did not kill any spiders while in the ruins, and lets you go. Keep in mind that there aren’t any spiders to kill in the ruins :v

• After the fight against Toriel in a pacifist run, go back all the way to the beginning of the game, where you fell. Toriel will be there attending to the flowers, possibly hinting that she made them grow there on purpose in order to save humans falling in the ruins.

• Keep petting Doggo, you’ll get some new dialogue, then he won’t be excited anymore after a while.

• When playing Ball (the minigame in the snowy area): in order to get a good score, you can either try to be as fast as possible… or wait until the ball is almost completely melted.

Artemis251:

• Save your game near the end of the game right before Sans judges you. After he has, reload and repeat a few times. He’ll eventually give you the key to his room.

I don’t want to spoil the fun just in case someone wants to go see for themselves, so I’ll play it safe.

• After getting the key to Sans room, you can find a second key there.

• After beating Asriel, go back to the room which this second key opens. There'll be a new little piece of text found by inspecting one of the drawers.

Artemis251:

• Additionally, there’s a hidden fight in Hotland on the screen above the place you get the Apron. I’m not sure exactly what triggers it, but I think it’s a fight on the screen. Try walking against the north limit to find a magic-tile bridge north.

• A sign is in the area with a hidden boss. It should display a date and a time. Check the sign at said date and time to fight them.

kota12:

When certain bosses are defeated, random encounters no longer happen in areas up to the boss fight. So if you need to make money, don’t fight Mettaton since there are no monsters that drop money after that.

Actually, things still spawn in the Core of a normal/peaceful playthrough. Genocide, though...

Artemis251:

I mean, I’m not the guy himself, but if I was a game’s creator, I’d be overjoyed in people slowly unraveling the many secrets and little details I put in my game. I know he has rants about how nothing is secret in video games any more and all that, but we can’t all play through the game with every scenario possible. Think about it, how many of us would have found, say, the secret boss in Cave Story without tips online? If there were means to discover the secrets ourselves (example, X-Ray scope in Super Metroid) I could see bein’ upset that people are sharing secrets. However, some of the stuff he’s hidden is so obscure (see: hidden boss in Snowdin) that it almost relies on word of mouth to learn about and experience yourself.

Sharing new things to do makes new playthroughs exciting, especially if you keep the tips vague so the other players have to try out the actions themselves to see what happens. So I hope people keep posting what to do and not what happens when you do it!

Oh, I only said that because of another secret that’s in the game.

(early game spoilers)

So I just got to the part where you fight Papyrus, and he spends most of the fight building up to his Special Attack, then never actually uses it.

I’ve spent the whole game so far sparing everything.

I keep dying during that fight, which really just means getting captured. Am I meant to be able to avoid this, or is it actually possible to get out of killing him or getting captured, just by continuing to Act or Spare?

You can drop Undyne's Letter. After that, if you go back and talk to her again, you’ll receive Undyne Letter EX. It seems to do nothing special, the only difference is that this one can't be dropped.

gotcha.

turns out I’m just bad at bullet hells

^And both of those songs are the same melody as the opening theme, and the song literally named Undertale.

While we’re on the subject of songs:

I’m sure there are other instances, and I look forward to finding more of them. It might be fun to dedicate a topic to the musical similarities, though.