Puzzles are a prominent component of the Underground and can also be found throughout Waterfall. Waterfall, however, contains significantly fewer puzzles than the ones found in the Ruins and Snowdin Forest which is explained in a call with Undyne where she explains that she hates puzzles.
God, I was supposed to build a puzzle for this room... But I HATE puzzles.Undyne
The Rock Puzzle
The Rock Puzzle is a puzzle where rocks come down from a waterfall and push the protagonist off to a bridge-like section at the bottom of the waterfall. In a phone call with Undyne, she explains that the puzzle was a result of lack of creativity and mentions that she built a huge pile of rocks upstream. Behind the waterfall in this puzzle is a room containing the Old Tutu.
On the Genocide Route, the rocks are absent from the waterfall.
The Bridge Seed Puzzles
The bridge seeds are buds of a flower found in Waterfall. When four of these seeds align in the water, they sprout into flowers where the protagonist can walk on.
The first bridge seed puzzle that the protagonist encounters requires the seeds to be used as a small gap. If the protagonist returns to this puzzle and calls Undyne in this room, she taunts the protagonist for not being able to jump the gap.
The second bridge seed puzzle has various solutions since the room is considerably larger and there is more water to put the bridge seeds on. This puzzle introduces the concept of the "bell-blossom" which causes the bridge seeds to regenerate to their original position if they have been moved.
The bridge seeds can be utilized in four different ways in this room:
- Two of these ways allow the protagonist to proceed to the next room.
- Only one is used after solving it and walking back into the room.
- One allows a sign that says "Congratulations! You failed the puzzle" to be read.
- One allows the protagonist to find a bench with an Abandoned Quiche under it.
On the Genocide Route, this puzzle is already complete, so the protagonist can simply walk through.
There was a glitch where if one places an extra four Bridge Seeds extending the path to the Abandoned Quiche, the protagonist then was able to walk from the eighth Bridge Seed and onto the water; however this was patched in Undertale v1.001.
The Piano Puzzle
The Piano Puzzle is a puzzle located north of the three-way intersection in Waterfall where Shyren is found. The room contains a piano that can be played with the "z" key and the directional arrows (for a total of five different playable notes) and a plaque saying that "the first eight notes are fine." The piano puzzle was built by Undyne as an excuse to place a piano.
The solution to this puzzle can be found to the right of the same three-way intersection by giving the statue being rained on an umbrella. From there, "Memory" plays, and the player must play the first eight notes of the song on the piano. The solution to this puzzle is "Neutral [•], Up [↑], Right [→], Neutral [•], Down [↓], (Neutral [•],) Down [↓], and Right [→]."
However, the puzzle allows the player to complete it by leaving out the 6th note (marked above with parentheses), as it is ambiguous whether that note is considered part of the song's melody or not. This makes it possible to solve the puzzle in seven notes.
In Undertale v1.001, the solution appears above the statue being rained on after giving it an umbrella and waiting a while. Interestingly, the solution that appears is the seven-note solution rather than the 'intended' (according to the plaque) eight-note solution.
The Box Puzzle
The Box Puzzle contains a box that is presumed to be pushed. This puzzle only appears by the time the protagonist has entered Hotland.
The Elder Puzzler found to the left of the puzzle rants about how monsters do not appreciate what makes puzzles great and complains that there are too many puzzles with lasers and moving rocks. They then proceed to say that there is no art in it and that the puzzles are not challenging enough. They then encourage the protagonist to solve the puzzle.
Upon touching the box, regardless of which angle the box is touched, the Elder Puzzler complains that the protagonist is pushing the box wrong and says "Bahh!!! Nevermind!!" when spoken to. Touching the box again after this just causes the Elder Puzzler to shout "Bah!"
- ↑ 1.0 1.1 "God, I was supposed to build a puzzle for this room... But I HATE puzzles. So I just put a huge pile of rocks upstream." - Undyne
- ↑ "Alphys helped measure out the mud tiles for this puzzle. It was a lot of work, but we got to make sand castles after. We're a good team. She's great at building them... And I'm great at wrecking them!!" - Undyne
- ↑ Undertale - Bridge Flower Collision Glitch - YouTube
- ↑ Screenshot