Mermaid Swamp

Mermaid Swamp is a freeware horror adventure game by Uri made in WOLF RPG Editor.

Rin Yamazaki and her college friends have their car break down in the mountains on a trip.
Fortunately, a kindly old man offers to let them stay at his house.
But there's a legend about the swamp outside the mansion...


(Content Severity: Some Discretion Advised)
Click here for content warnings.

Blood, gore, and death.
Body horror.
Drowning.
Some mild nudity.
Cannibalism in one ending.
Jumpscares.
Swearing.



Download Mermaid Swamp (Remake) | (Mirror)
(Chrome may falsely flag the download as malicious, but it's safe to ignore.)

Voiceless Version | (Mirror)
This version removes the main voice acting. It is generally only recommended if you can't download the full game.

Original Version | (Mirror)

Supported Platforms
The game's engine is made for Windows only, with no native support for other platforms. To play on Mac, you can try a general-purpose tool like WineBottler.




Usage Notes

Videos are allowed, but should not be profited off of, with the exception of YouTube monetization. Live streams are allowed.

Fanworks are generally allowed and can be sold. However, you should not sell anything that uses any specific resources from the game.

[1] Japanese rules page



Troubleshooting

Make sure to extract the game to its own folder instead of running directly from the ZIP file. If you don't do so, any saves made will be lost the next time you run the game.

If pictures aren't appearing where it seems they should, you must run the game as an administrator. Right-click Game.exe, go to Properties, and under the Compatibility tab, check "Run this program as an administator." (The first such picture should be an illustration of the group in the car.)

You may get an error about Game.dat not being found if the game folder's filepath contains special characters (accents, etc.). This can be fixed by moving the game folder somewhere without special characters in the path. There may also be errors when running in certain locales, but it should always work in English or Japanese locale.



Screenshots

Screenshot
Screenshot
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Walkthrough

I've provided a walkthrough if people get stuck. Click or highlight the black boxes to show spoiler text.

Walkthrough (Remake)

Intro

Everything up to the decision to look for a map should be straightforward.

(When Rin remembers she needs to charge her phone, use the Cellphone or Charger from the items menu on the desk lamp in Rin's room.)



Day 1

Check on Yuka and you'll hear a sound as you go to leave. Check the dresser to find a Key (Bedroom).

Talk to Yuuta, who's looking at the painting in the 1F dining room. Follow him to the 1F southwest hall and talk to him again. Then talk to him again to the 1F southeast hall.

Read the book in the study (top-left of 2F). Seitaro is also there during the day, so ask him about anything you come across.

Hint: "The middle of the world" refers to the paintings in the symmetrical rooms on the second floor.
Answer: After reading the book in the study, check the shelf in the right room and move it to find Documents in the wall. Seitaro can read them for you.

Use the bedroom Key on the middle door at the south end of 2F. Check the right bed for a Clip and the left shelf for a Note.

Hint: The note gives you directions for a certain room. The circles represent large eyeballs.
Answer: Go to the room with the two fish tanks on 2F, start in front of the left one, and take 5 steps down, 4 right, 1 down, 5 right, 4 up. You'll end up on a tile on the right side. Check the floor there to find a News Clipping. You must have the Note to find this.

Use the Clip to lift the latch on the Japanese room looked from the inside on 2F. Read the diary on the desk.

Check the pot in the upper Japanese room. Go to the 1F kitchen and take the Cooking Chopsticks. Use them to pull a Key (Master's Room) out of the pot. Go down into the lower Japanese room to trigger a brief scene. Check the open closet for the Old Paper. (Seitaro can read it for you.) Go unlock the master's room (bottom-left door on 2F) and be sure to read the diary on the shelf in the top-right.

After doing everything you can, Seitaro will talk to you in the 2F hallway. After getting the Lantern and Lighter, go to Yuuta's room.



Night 1

Use the Lighter to open the bottom-right 2F door with wax in the keyhole. Read the letter on the desk.

Go to the piano room and check the left painting for a Key (Storeroom). Use it on the door near the entrance on 1F. Inside the storeroom is some Firewood. If you take the Firewood, you'll be forced into using it to light the fireplace in Yuka's room.

If you light the fireplace: Yuka and Yuuta will die.
If you don't light the fireplace: Yuka and Yuuta will live.

Leave the main building and head right to the old mansion. The door has a passcode.

Hint: The diary in the master's room says that he locked it "with that sorrowful year and month as the key." What else provides a year and month?
Answer: 197208, from the date on the article.

Go up the middle stairs. Walk toward the windows, then back out. Check the window. Head to the swamp, then go to bed after the scene.



Day 2

Go towards Yuka's room. Wake up Seitaro.

Go to the old mansion and get the Key (Study) from the bath.

Unlock the study (west side of 1F). Check the shelves on the left. Push the table from the hall outside up to the shining object to get the Wind-Up Key.

After trying to walk up the stairs, return to the main mansion's storeroom for a Mop. Use it to clean the sludge on both stairways.

Go into the makeup room (second door on west side of 2F, into the left side-room) and read the writing on the mirror. Ask Seitaro what it means.

Note: If you never read the diary in the lower Japanese-style room on 2F of the main mansion (the one you had to open with the Clip), you must do that before you can begin the following puzzle.

Answer: Find the clock on the east side of 1F and use the Wind-Up Key to start it. Set the long hand to 12 (0 minutes). Then set the short hand to 8, then 4, then 10 (it'll click after each) for a Bottle of Liquid.

Read the diary in the nursery (west side of 1F). Go to the room with eight fish tanks (east side of 2F) and reach into the second from the bottom-right for a Plastic Object. Ask Seitaro what it is, then use the Boat Button on the motorboat outside.

Ask Seitaro in the study about the Bottle of Liquid. Check the hole on east 2F if you haven't yet. Then you can use the Bottle of Acid to melt the nails on the boarded-up door and get the Planks.

Use the Planks to enter the door with the hole in front. Get the Golf Club from the bag, the Hammer from the toolbox (if you've found the fireplace passage), and read the diary in the left bookcase.

Once you've put the Boat Button in the boat and obtained the Golf Club, you'll get a call inside the room that had the hole in front. Answer it, then go back and check on Yuka.

If you lit the fireplace, Yuka dies. Yuuta will run off and stab himself in the kitchen.
If you didn't light the fireplace, Yuuta will chase you and you have to destroy all the Ophelia paintings. Two are in the bottom corners of 1F, one is in the dining room in lower-left 1F, two are in the upper corners of 2F, and one is in the bottom-left door on 2F. Then there's one more in the old mansion: the rightmost door on the west side of 1F.

Go outside and left into the mountains. Find your way through. As Seitaro, do the same.

In the village, knock on all six doors. Then go left to the gravesite. Read the sign, and go left again to find Rin.

Go out to the swamp.



Night 2

Get the Kitchen Knife. (Depending on the path, it's either in the kitchen or just inside the old mansion.) Go to the bedroom in the old mansion (west side of 2F) and use the Kitchen Knife to cut open the left bed pillow for a Key.

Use the Golf Club to open the right side of the closet in the maids' room (east side of 1F, with the two beds on the floor) for a Key (Boiler Room).

Use the Key (Boiler Room) to open the boiler room outside the old mansion. Get the Engine Key. After you leave, a Stone Picket will fall over; take it.

Check the fireplace in the large parlor (middle stairs) to find a hidden passage. To enter it, you need three items:

Rope: Enter the dressing room (2F east hall) with the Key from the pillow. You must solve the puzzle on the wooden box.

Hint: Refer to the flower book in the second door on west 2F, and something else close to the box.
Answer: Match the colors of the clothing to the colors at the bottom of each flower's entry. From left to right: Pomegranate, Wisteria, Plum, Gardenia, Spiderwort.

Stone Picket: Take the picket outside the old mansion that falls over after you get the Engine Key.

Hammer: From a toolbox in the master's room in the old mansion (east 2F, with the hole in front).

Use any of the items at the fireplace, and get the Swamp Map in the secret room.



Day 3

Head outside.
Accept: Game over.
Refuse: Start running.

Go up to the west side of the second floor, then into the right door.
Dodge: Seitaro dies.
Don't dodge: Seitaro lives.
Run out of time: Seitaro dies.
If necessary, enter the third door from the left downstairs, then go to the swamp.

Look at the Swamp Map. Go to the study to learn how to tell the orientation. Use the Wristwatch in front of the swamp to find your way.

Push the motorboat outside the old mansion, then use the Engine Key on it to cross the swamp.

Hint: Check the Swamp Map for a clue for what to do on the other side.
Answer: Check the ground to the right of the largest rock.



Endings

Yuka, Yuuta, and Seitaro die: Yaobikuni
Only Yuka and Yuuta die: Forever Deep
Only Seitaro dies: Secrets
All survive: Underwater Dream

Goals List (Remake)

#1 Y-Yeah...!
Talk to Seitaro in his room before going to the swamp monument.

#2 Seen Those Paintings?
Talk to Yuka in her room before going to the swamp monument.

#3 The Swamp Outside
Talk to Yuuta in his room before going to the swamp monument.

#4 Tonight's Menu
Talk to Tsuchida in the kitchen before going to the swamp monument.

#5 First Floor Art
View all the paintings on the first floor.

#6 Good Night
Check on Yuka in her room after dinner.

#7 Brief Rest
Talk to Seitaro out by the swamp after dinner.

#8 Reception
Talk to Yuuta in his room after dinner.

#9 How About Tea?
Talk to Tsuchida in the Japanese room after dinner.

#10 It's Morning, Y'Know
Talk to Yuka in her room in the morning before going to the living room.

#11 Fell Asleep?
Talk to Yuka in her room after Tsuchida leaves and before Rin's bath.

#12 Joking!
Talk to Yuuta in the living room after Tsuchida leaves and before Rin's bath.

#13 Japanese Mermaid
Talk to Seitaro in the Japanese room after Tsuchida leaves and before Rin's bath.

#14 Shivering
Check on Yuka in her room after Rin's bath.

#15 No Wonder...
Talk to Seitaro in the living room after Rin's bath.

#16 A Prank?
Talk to Yuuta in his room after Rin's bath.

#17 Morning Routine
Talk to Seitaro in his room after waking up from the dream.

#18 Breakfast
Talk to Yuuta in the kitchen after waking up from the dream.

#19 Ambulance!
Talk to Seitaro right after he tells you to call an ambulance.

#20 What Happened?
Talk to Yuuta in the hall right after Seitaro tells you to call an ambulance.

#21 Garden of Delights
View both paintings in the 2F children's rooms.

#22 Fishy-Fish
Read both sketchbooks in the 2F children's rooms.

#23 Second Floor Art
View all the paintings on the second floor.

#24 Let Me Rest
Talk to Seitaro in his room after night falls.

#25 Don't Dare Enter
Try to enter Yuuta's room after night falls.

#26 Kids' Drawings
View both of the children's drawings in the 2F room with the piano.

#27 Sleeping Soundly
Check on Seitaro in his room after Yuuta heads to the old mansion.

#28 Slight Relief
Check on Yuka after lighting her fireplace.

#29 Out Like a Log
Talk to Seitaro in his room after waking up from the Chiyo and Chie dream, before breakfast.

#30 For Now...
Check Yuuta's door after he comes out of Yuka's room.

#31 Servant Wisdom
Read the rules on the wall in the maids' room.

#32 Grudge
As you exit the makeup room in the old mansion, you'll hear a sound. Check the left bureau to read the message inside.

#33 Stinky!
Sniff the Bottle of Liquid before asking Seitaro what it is.

#34 Patriarch's Diary
Read the diary in the master's room in the old mansion.

#35 Harsh Words
Knock on one of the doors in the village after the scene with the old woman.

#36 Rest
Check on Seitaro in his room after diving into the swamp.

#37 Generator?
Check the generator in the boiler room.

#38 Missing Axe
After returning from the fireplace passage, check the fireplace.

#39 Underwater
Accept Seitaro's offer.

#40 Escape Impossible
During the Seitaro chase, try to leave the old mansion.

#41 Left Undone
During the Yuuta chase, try to leave the mansion before destroying all the paintings there.

#42 A Week's Worth
Talk to Yuuta after the Yuuta chase.

#43 Off I Go
Talk to Yuuta as Seitaro when Rin goes missing. (Must be alive.)

#44 Weirdo!!
Check on Yuuta in his room after diving into the swamp. (Must be alive.)

#45 Return It
Give the Hairpin back to the mermaids in the underground room on the best ending.

Walkthrough (Original)

Intro

Everything up to the decision to look for a map should be straightforward.



Day 1

Check on Yuka and you'll hear a sound as you go to leave. Check the dresser to find a key (bedroom).

Talk to Yuuta, who's looking at the painting in the 1F dining room. Follow him to the 1F southeast hall and talk to him again. Then talk to him again to the 1F southwest hall.

Read the book in the study for a hint. (Seitaro is also there during the day, so ask him about anything you come across.)
Hint: "The middle of the world" refers to the paintings in the symmetrical rooms on the second floor.
Answer: After looking at both paintings, check the shelf in the right room and move it to find documents in the wall. Seitaro can read them for you.

Use the bedroom key on the middle door at the south end of 2F. Check the bed for a wire and the right shelf for a note.
Hint: The note gives you directions for a certain room, and Rin is correct that the circles refer to eyeballs. Where have you seen eyeballs that big?
Answer: Go to the room with the two fish tanks, start in front of the left one, and take 5 steps down, 2 right, etcetera; you'll end up on a tile on the right side. Check the floor there to find a newspaper article.

Use the wire to lift the latch on the Japanese room looked from the inside on 2F. Read the diary.

Check the pot in the upper Japanese room. Go to the 1F kitchen and check the cupboard for cooking chopsticks. Use them to pull a key (master's room) out of the pot.
Go unlock the master's room (bottom-left door on 2F) and be sure to read the diary there.
Go down into the lower Japanese room and check the closet for an old piece of paper. Seitaro can read it for you.

After doing everything you can, Seitaro will talk to you in the 2F hallway. After getting the lantern and lighter, go to Yuuta's room.



Night 1

Use the lighter to open the 2F door with wax in the keyhole. Get the letter from the desk and read it.

Go to the piano room and check the left painting for a key (storeroom). Use it (the door is near the entrance on 1F) and get some firewood.

If you light the fireplace in Yuka's room: Yuka and Yuuta will die.
If you don't light the fireplace in Yuka's room: Yuka and Yuuta will live.
Note that you can basically delay lighting it for a fair while (that is, until just before the point where it starts making a difference).

Leave the main building and go to the old mansion. The door has a passcode (but only once you have all the hints).
Hint: The diary in the master's room says that he locked it "with that sorrowful year and month as the key." What else provides a year and month?
Answer: 197208, from the date on the article.

Go up the middle stairs, and when you hear a noise, check out the window. Return to the swamp, then go to bed after the scene.



Day 2

Check on Yuka. Wake up Seitaro.

Go to the old mansion and get the key (study) from the bath.

Unlock the study (west side of 1F). Push the table from outside up to the shelves to get the spring.

After finding the sludge on the stairs, return to the main building's storehouse for a mop. Use it to clean the sludge. Go into the makeup room (west side of 2F) and read the writing on the mirror.
Answer: Find the clock on 1F and use the spring to start it. Set it to 8, as indicated by the mirror, for a bottle of liquid.

Read the diary in the nursery (west side of 1F). Go to the room with eight fish tanks (east side of 2F) and reach into the second from the bottom-right for a button.

Ask Seitaro in the study about the bottle. Use the bottle to melt the nails on the boarded-up door and get the planks. Use them to enter the door with the hole in front (west side of 2F).
Get the golf club from the bag and read the diary.

After the call, go back and check on Yuka.
If you lit the fireplace, Yuka dies. Yuuta will run off, eventually stabbing himself in the kitchen.
If you didn't light the fireplace, Yuuta will chase you and you have to destroy all the Ophelia paintings: first the six in the main building, then the one in the old mansion.

Go outside and left into the mountains. Keep walking. As Seitaro, do the same.
In the village, knock on the doors, then go left to the gravesite. Read the sign, and go left again to find Rin.

Jump in the swamp.



Night 2

Get the knife. (Depending on the path, it's either in Yuuta's room or the kitchen.)

Go to the bedroom in the old mansion (east side of 2F) and cut open the left bed's pillow for a key. (You must have read the diary in the nursery to learn about it first.)

Check the fireplace in the large hall (middle stairs) to find a passage down. To enter, you need three items:
Rope: In the dressing room (2F east hall), entered using the key from the pillow.
Picket: The fallen stone picket outside the old mansion.
Hammer: Toolbox in the master's room in the main building (bottom-left on 2F).

Get the map in the secret room below the fireplace.



Day 3

Accept: Game over.
Refuse: Start running.

Go into the leftmost room on the second floor.
Dodge: Seitaro dies.
Don't dodge: Seitaro lives.
Run out of time: Game over.

Talk to Seitaro in the study, or check the gleaming book in the study to learn how to tell directions. Check the map in front of the swamp to find your way.

Open the closet in the old mansion maids' room (east side of 1F, with four beds) for the boiler room key.

Go into the boiler room outside the old mansion and get the engine key.

Use the engine key and button (refer to Day 2 if you didn't get it yet) on the motorboat outside the old mansion to cross the swamp.
Hint: Check the map for a clue for what to do on the other side.
Answer: Check the ground to the right of the big brown rock.



Endings

Yuka, Yuuta, and Seitaro die: Yaobikuni
Only Yuka and Yuuta die: Forever Deep
Only Seitaro dies: Secrets
All survive: Underwater Dream



Extra Links

These contain spoilers for all aspects of the game. Only read them after you've beaten it fully.

Translation Notes
Setting and Considerations Booklet



Woe be to those who near the swamp.