A fantastic amount of effort has been put into Undertale, from its retro art style to its challenging bullet-hell combat. But, above all else is the attention to detail placed into the encounters with its characters. Many memorable interactions are impossible to experience in one playthrough alone. There are many ways to play through the game, but the two routes with the most significant differences are Pacifist and Genocide.
The prime example of how Genocide and Pacifist routes change the experience is with Flowey. Each route will give the player a very different perspective on Flowey and alter the player's interactions with him. These changes make replaying the game worth pursuing time and time again to learn more about him. Warning: Reading onwards will involve some significant spoilers for Undertale.
9 Pacifist: Flowey mocks the player for sparing Toriel
After sparing Toriel and finally heading out of the Ruins, there is one last encounter with Flowey to get through. He will belittle the player for choosing to spare everyone. This is the complete opposite of Flowey's philosophy of "It's kill or be killed." Flowey will proceed to warn the player that their willpower will eventually crumble. Flowey is convinced that the protagonist will resort to violence or give up. When that time comes, Flowey will be waiting to retake control of this world.
This interaction with Flowey gets even more complex with further playthroughs. Flowey seems to remember every iteration of the story. If the player spared Toriel this time but killed her in a previous playthrough, Flowey will remind the player of that murder, even if Toriel cannot remember. This makes for a haunting encounter for any remorseful player.
8 Genocide: Flowey Recognizes The Player As An Old Friend
Suppose the player has defeated everyone in the Ruins, activating the genocide route in full force. In that case, the interaction with Flowey at the end of this area will play out very differently. Flowey will recognize that the player does not have a soul. They are also confident that the player is their old friend Chara.
Flowey seems thrilled to be reunited, but this does not stop him from being as terrifying as always. Flowey will hint at a devious scheme to become even more powerful and is eager for the player to join him in destroying this world. This interaction provides an unsettling familiarity between the player and Flowey and certainly sets up the tone for a genocide route right away.
7 Pacifist: Flowey's Origins Are Revealed
Near the end of the game, the player will take a trip through Asgore's home. Players will eventually discover that this was where Flowey (Asriel) and the first human grew up. Instead of interacting with Flowey himself during this section, players will hear of his backstory from the wonderful monsters they have met along the adventure. This story is unavailable if players are going through a genocide playthrough.
Following this, in the True Pacifist playthrough, players will get to venture deeper into Alphys' laboratory and learn more about how Flowey was created. It is quite a fascinating adventure through the creepy, abandoned laboratory, discovering how Flowey came into existence due to Alphys injecting determination into golden flowers.
6 Genocide: Flowey Tells His Side Of The Story
During the visit to Asgore's house, players taking the genocide route will get the chance to interact with Flowey directly once more. They will get to hear his side of the story and learn about the chilling first moments of Flowey's existence. Flowey will explain to the player how he awoke in a flowerbed, scared and alone. Asgore eventually found him, and Flowey could not understand why Asgore was so emotional. Flowey slowly learned that he lacked empathy. He had no feelings whatsoever. Flowey's story goes on from there, detailing his incapacity for love, lack of a soul, and the discovery of his power to manipulate the world around him.
It is a tragic story that adds a lot of depth to Flowey's character. Although a lot of what Flowey has done is unforgivable, players can feel sympathy for him and understand his motives a little better.
5 Pacifist: Flowey's True Form Is Revealed
The True Pacifist route is the only way to see Flowey in his true form. During this final confrontation with Flowey, where it seems like things couldn't get any worse, he transforms into Asriel Dreemurr, the God of Hyperdeath. It is a monstrous version of Toriel and Asgore's son, and it is quite a scary encounter.
But, if the player stays true to their pacifist ways, they will eventually get the chance to redeem Flowey. He will revert to an ordinary Asriel, a scared, lonely child who just needs a hug. This encounter is very emotional and packs quite a punch for players. It is incredibly satisfying to help Flowey see the error of his ways and finally feel something again. Players can even head to the very start of the Ruins to see that Asriel has changed his philosophy to "Don't kill and don't be killed."
4 Genocide: Flowey Pleads For His Life
Unlike the pacifist run and the neutral run, which involves a great battle with a photoshop version of Flowey, a genocide run will not include a final epic fight with the sadistic flower. This is a relief to the player after having to handle the challenging last encounter with Sans.
The player discovers when they meet Asgore that Flowey was attempting to warn him about the protagonist. When Asgore is easily defeated, Flowey, in the act of desperation, will destroy Asgore's soul and plead with the protagonist to be spared. The player has become more of a monster than Flowey could ever be, and it's enough to spark fear into the sentient flower. The player has the chance to brutally destroy Flowey in quite a horrific conclusion to a dark playthrough of the game.
3 Pacifist: Flowey Offers Advice To Get The True Pacifist Ending
The only way to get the True Pacifist ending to the game involves playing through a neutral run first. At the end of this playthrough, as long as the player has been kind and decides to spare Flowey, the flower will have a moment of clarity and have a fantastic character arc.
Flowey wants to help the player now and offer some invaluable advice for the start of their next playthrough, rather than be his usual mean-spirited self. If the player killed some monsters during the last playthrough, Flowey will remind the player that they must not kill anyone. If the player has avoided becoming a murderer, Flowey will instead suggest that the player befriends everyone they can. With Flowey's advice, the player can finally head off to complete the True Pacifist ending. Unfortunately, he offers no guidance on finding Temmie Village.
2 Genocide: Flowey Gets Annoyed If You Abort A Genocide Run
If the guilt gets too much for players attempting the genocide route (The game certainly knows how to make players feel incredibly sorry for their actions), they can always abort the playthrough and head back to the start to try again.
Flowey will not forget the player's actions, though. He is aware of everything and will not be amused. He will criticize the player at the start of their next playthrough before concluding that the player is simply wanting to have fun toying with the underground residents. Flowey feels confident that the player will return to wreak havoc with him soon enough.
1 Both: Flowey Is Always Watching
No matter if the player is making countless friends and bringing peace to the underground or if they are on a mass-murdering rampage, there is one detail about Flowey that will always remain the same. Flowey is constantly spying on the player.
It can be tough to spot him, as it requires backtracking after significant moments during the story. If the player heads back to a previous location, they will be able to spot Flowey for a mere second before he burrows away back underground. Even when it seems like Flowey is nowhere to be seen, he is always nearby, observing from afar. After all, Undertale is very much Flowey's game as much as it is the players.