Quake

FOR PC PLAYERS:
Hit the ~ key and enter "map e2m3"

Now enter the usual "god" and "noclip" into the console commands.

Fly around until you see a BLUE WALL underwater with a green fish painted on it. It's really hard to miss. Turn off no clip here, pick all the stuff, wait a few seconds and you will get the Well of Wishes achievement. This took about a minute to pop for me, while all other were instant.

If you want the secret level achievement as well, you can go ahead and grab that easily. Turn noclip back on and just through the blue wall and up a little bit you will find a portal. That is your secret exist portal (this one took like 1 minute for me to pop, so be patient, it's the right portal).

(please note level select seems to nullify some achievements, but using the command code work with no problems)

The Well of Wishes is found in E2M3: The Grisly Grotto. This is a written guide + images to find the secret, a video clip is also provided at the bottom if you prefer. It's worth noting that the secret exit for this episode is also in this level not far from this easter egg; see details here:

Solution for Nevermore In Quake

Towards the end of the level you will come to a hallway filled with nail traps shooting out. At the end of the hallway is a button on the left to extend a bridge, enemies will run along the bridge so take them out. There's also another enemy to the right on a ledge when you move onto the bridge.



Step on to the bridge and do a 180. On the right is an alcove you can jump to with a Quad damage, I recommend saving that for when you go down the bridge later (there's a knight and shambler). From the alcove, you can see a very thin ledge along the wall. Carefully walk along it and jump into the window at the end.



Run down the hallway and into the water. You will find the Dopefish easter egg and two powerups, and the achievement will unlock. You can follow a path around the left (a wall will open up) to get back to the level.

This is in Crypt of Decay (E2M3).

STEP 1: Complete the level and reach the exit.

STEP 2: Facing the level exit, turn around and head outside to the room with the two connecting bridges. Standing on the bridge closest to the room with the spike shooting traps while also facing said room, if you look to your right you'll see a door with no obvious path to access it. However, if you jump to the right of the spike trap room outside, where there's a quad damage pickup, you'll see you can follow a thin ledge that goes to the door. Doing so and going through the door will grant you three health pickups and a drop to a pool of water.

STEP 3: jumping inside the pool of water and heading forward should reveal a mural of dopefish, which while being in proximity to should trigger the achievement.

here's a simple guide to help you get this achievement.