- Napstablook 的家
- Napstablook 的堂（表）兄弟（姊妹）的家
- Gerson 的商店
- Temmie 村莊
- 駝獸（Ferry Monster）
- Gaster/神秘男子 的房間（需要修改 Fun值）
Ancient glyphs adorn walls throughout Waterfall. The color palette of this region is mainly purple and blue with the occasional black abyss. Mushrooms, Echo Flowers, and gems within the walls glow bright blue. True to its namesake, pools of water often provide the atmosphere in Waterfall, and the ceiling drips with water in some areas.
Waterfall Entrance to Initial Sea-Grass 编辑
在瀑布的第一个房间, the protagonist speaks to Monster Kid, Sans, and the Echo Flower Explainer. A small waterfall flows through this room, and an Echo Flower and Sans's sentry station are against the north wall. Between Sans's sentry station and the Echo Flower is a SAVE point. Snow covers Sans's sentry station and his station blocks access to a wooden door. From this room, the protagonist can go with Sans to Grillby's via a shortcut through the right wall.
After progressing right, the protagonist encounters a puzzle that involves dodging rocks that are going down the waterfall as well as a box. If a rock pushes the protagonist over the edge of the waterfall, they land on a wooden bridge that has an Echo Flower on the rightmost end. Backtracking to the left allows the protagonist to attempt to cross the waterfall again or access the hidden room behind the waterfall. The Old Tutu resides in this hidden room.
To the right of the waterfall room, a room with a patch of tall grass provides a cutscene of Papyrus and Undyne. Papyrus stands on the lighter side of the room while Undyne stands in the shadows. Undyne nearly attacks the protagonist but stops when she remembers that the sea-grass is used for scientific study.
A few red gems and blue gems are in this room, along with three stalagmites near Undyne. After the protagonist exits the tall grass on the right, Monster Kid appears from the grass and celebrates seeing Undyne.
Initial Sea-Grass to The Wishing Room 编辑
Progressing right, the protagonist encounters 橋樑種子. The first room serves as a tutorial of Bridge Seed mechanics, and the protagonist crosses the waterfall in the room after lining up four Bridge Seeds. Using the right exit of the room, the protagonist enters a larger room with another Bridge Seed puzzle within it.
After taking a few steps forward, the protagonist encounters Aaron. This encounter is scripted.
Along with four Bridge Seeds, this room contains four glowing mushrooms, a sign in the middle of a waterlogged area, a Bell Blossom that retrieves the seeds, and a sign describing the Bell Blossom. The sign in the bottom left of this room reads "Congratulations! You failed the puzzle!" The protagonist can solve the Bridge Seed puzzle multiple ways.
The protagonist can use the Bridge Seeds to create a bridge offscreen to the right of the room. In this room, there is an Echo Flower and a bench with the Abandoned Quiche beneath it.
If the protagonist approaches the top left exit of the Bridge Seed room, Papyrus calls and inquires what the protagonist is wearing.
The Wishing Room to Ferry Dock 编辑
The next room is the wishing room which contains many Echo Flowers and blue, glowing gems on the ceiling. As the protagonist progresses right, a telescope pointed at the ceiling offers a clue to check the northern wall to find the exit fo the room.
The northern exit leads to a room with a wooden bridge and dark water in which many Water Sausages grow. On the north wall are many ancient glyphs. At the end of the wooden dock, the protagonist steps on a small raft that drifts to the right.
Undyne's first spear barrage occurs in the next room. The protagonist flees from Undyne's spears along a wooden dock surrounded by black water. Undyne stands to the north of the protagonist and directly behind a row of rock pillars. The protagonist escapes Undyne by hiding in tall sea-grass.
Ferry Dock to Onionsan 编辑
After leaving this room through the right exit, the protagonist reaches the third SAVE point. Also in this room is an Echo Flower, a mouse hole, and a piece of cheese. The Echo Flower, which is to the right of the mouse hole, squeaks when the protagonist interacts with it.
Continuing right, the protagonist exits the room and sees Sans standing next to a telescope. To his right is another dimensional box. Sans attempts to prank the protagonist with the red-eye telescope. Exiting through the wooden door on the north wall of this room leads to another small room with the Nice Cream Guy in it. There is also a Punch Card box, a blue, glowing mushroom, and defiled ancient glyphs in this room.
If the protagonist backtracks from this room and travels right from Sans's telescope, they encounter "Loren" and, continuing right, the small bird. The protagonist cannot use the small bird yet, as they are on opposite sides of a chasm of bright blue water.
The room with "Loren" in it spans a large area horizontally and vertically. The color palette reverses in this room, and the water appears bright blue while the land appears black. As the protagonist traverses this room, they encounter a few Echo Flowers and can also find the Ballet Shoes in a tuft of tall grass.
Before the protagonist crosses a wooden bridge, Papyrus calls them again and explains that he told Undyne exactly what the protagonist is wearing; he clarifies that he was trying to be loyal to the protagonist and Undyne.
Continuing on, the protagonist enters a long, horizontal room with a narrow black path leading to the right. As they progress down this path, Onionsan appears and talks to them. The protagonist then leaves through the right exit and encounters Shyren in the next room.
Onionsan to Garbage Dump 编辑
This room has two small, white waterfalls that flow from the top to the bottom of the screen and always stay in the foreground. To the north of this room, the piano puzzle awaits the protagonist. The protagonist opens the door to the Artifact Room by playing the melody that echoes through the area.
The Artifact Room itself contains a red orb on a pedestal and glyphs that cannot be read because the protagonist cannot stand directly in front of them.
Backtracking and heading to the right from the room with Shyren's battle, the protagonist encounters more ancient glyphs that inform them of Boss Monsters. Continuing to the right, they see an ancient statue that has water dripping on it from the ceiling.
Exiting this room through the right exit leads the protagonist to a room with a white waterfall in the foreground, a bucket of umbrellas, and a sign encouraging them to take an umbrella. Progressing right, they walk through a waterlogged room that has many waterfalls and reflective pools within it. Monster Kid walks alongside the protagonist for the duration of this room.
After the duo reaches the end of this room, they enter a two-dimensional room with New Home off in the distance. The game returns to an overworld scheme after the protagonist exits this room to the right.
After Monster Kid helps the protagonist climb onto a ledge, the protagonist progresses to the next room without them after Monster Kid gives them the go-ahead.
The next SAVE point is in the room immediately to the right of the ledge. There are also more ancient glyphs on the walls that detail The War of Humans and Monsters. Exiting this room to the right, the protagonist walks on another wooden bridge where Undyne antagonizes them. After reaching a dead end of the bridge, the protagonist falls into the garbage dump after Undyne slices the bridge in two.
Garbage Dump to Undyne's Crag 编辑
Mad Dummy is fought. Napstablook invites the protagonist to their house.
Small bird may be approached. Napstablook may be spoken with at his house or his snail farm, and offers a gambling opportunity at the latter. Mettaton's house is next door. Gerson may be bartered with, and the river person is present if the protagonist has reached Hotland. A dimensional box is present. Mazes involving lighted paths must be solved, and the Temmie Village may be found. Undyne attacks, but is inadvertently stopped by Monster Kid. Monster Kid then falls from a bridge and is saved by Undyne or the protagonist. Undyne speaks to the protagonist.
Undyne must be fought. The protagonist may then proceed into Hotland.
- 當你在 Sans 的昂貴望遠鏡右方或直接從 Nice Cream 那朝下查看南方的牆，你會得到以下訊息：「寶石在南方牆面上壯麗的圖案中閃爍著。」「你可以從這個角度看到南方的牆是件很棒的事。」
- 在有落石的房間中觀察瀑布，玩家可以發現一台隱藏的攝影機，這些攝影機是由 Alphys 博士所操縱，來讓她跟隨玩家的冒險。
- 這一區域被推論說和八名人類有關，特別是其中的藍色靈魂，因為 舊芭蕾舞裙、芭蕾舞鞋跟藍色靈魂的相關物品都出現在這裡。此外，瀑布 (原聲帶)，在這區域裡播放的主題曲，聽起來和管絃樂芭蕾舞主題有幾分相似。最後，瀑布的原聲帶可以用悲劇的、哀傷的，也就是「藍色的」來形容。
- 在屠殺路線有一個相關的漏洞：如果玩家在第一次遭遇 Undyne 時，也就是躲在草叢中那次，往左走而非往右走，那麼他們會看到 Papyrus 和中立路線或完美路線一樣出現在那裏。
- 當你在屠殺路線的橋上(Undyne的地區前),如果你未把所有怪物殺光,會有紅色的字出現:「Strongly felt (未殺的怪物數量)left shouldn't proceed yet[[[我強烈感受到還有]](未殺的怪物數量)沒殺 不應該繼續前行]」
|地表世界||伊波特山 ● 地下世界|
|廢墟||蜘蛛烘焙坊 ● 居所 ● Toriel的家 ● 廢墟走廊 ● 廢墟大門|
|雪町||雪鎮森林 ● 神秘的門 ● Grillby's ● 骷髏之家|
|瀑布||垃圾場 ● Undyne的家 ● 閃電蝸牛 ● Temmie村莊 ● 神器密室 ● Gaster的房間|
|熱地||實驗室 ● 藝術俱樂部 ● MTT渡假村 ● 核心 ● 真正的實驗室|
|新居||Asgore的家 ● 屏障|