Mycopunk How to Open Bunker: Switches, Red Keycard, and Bunker Buster

Confused by Mycopunk bunkers? Learn the Gravity Farms switch puzzle, the red keycard bunker, and how to fix the Bunker Buster achievement.

Trying to figure out Mycopunk how to open bunker can feel like solving three puzzles at once, because the game uses the word “bunker” for more than one kind of locked door. If you are standing in front of a sealed hatch with no obvious prompt, the answer depends on whether you are on Gravity Farms, on a procedural map, or in the Flourishing Desert. This guide breaks down each case, explains what the red keycard is for, and covers the Bunker Buster achievement. The most useful way to approach Mycopunk how to open bunker is to identify the location first, then match it to the right mechanism.

Why Mycopunk How to Open Bunker Has Three Different Answers

Community documentation checked on 2026-10-23, with patch 2.0.2 as its guide context, separates the confusion into three locations. They are not variations of the same door, and they do not give the same reward. Mixing them up is the main reason players get stuck.

What you are looking at	Where to go	What unlocks it	What you get
Gravity Farms bunker	Gravity Farms, roughly toward the big ring from the landing zone	Three switches hidden behind breakable walls	A transponder or consumable that opens the Ground Zero mission and eventually the Globbler
Locked bunker POI	Uncharted procedural maps	Map RNG; there is no fixed coordinate	Red keycard
Flourishing Desert door	Flourishing Desert	Red keycard	Containment mission

The details below come from community documentation of the bunker, red keycard, and three doors and a 2025 Globbler walkthrough. For the game itself, see Mycopunk on Steam.

Two of these are easy to confuse because older videos and guides use “bunker” for the Gravity Farms switch room. The third is a separate red keycard chain that points toward the Flourishing Desert. If your search for Mycopunk how to open bunker led you to a screenshot of a rock with a pinned coordinate, you are probably looking at the procedural POI, and that pin may not apply to your map seed.

The Gravity Farms Bunker: Three Switches and a Transponder

Start with the version most players mean when they search Mycopunk how to open bunker after watching a Globbler guide: the bunker on Gravity Farms with three inactive lights. A community walkthrough published on July 11, 2025 describes the route from the landing zone as almost straight toward the big ring. The bunker is the landmark; the switches are scattered around it behind breakable walls.

Switch 1: Magenta Light, Right Side

From the bunker, head right toward the map border. Look for a cluster of large purple mushrooms and a silo with a breakable wall. Break in and flip the switch inside. Community reports differ on color labels, so use the silo as the landmark rather than the exact light name.

Switch 2: Cyan Light, Back Left

Go back left from the bunker and look for a green or cyan building with a side entrance. Inside, a breakable wall hides another switch. Again, the building and the breakable wall are the reliable markers.

Switch 3: Yellow Light, Past the Dome

Head due left toward the dome, then continue to the globe-shaped structure shown in community guides. A breakable wall on its side holds the final switch. With all three lights active, the bunker opens.

What Happens After the Bunker Opens

Community reports describe the reward as a consumable or transponder that unlocks the Ground Zero mission; one older guide calls it a Scorched Transponder. That is not the red keycard. Ground Zero has its own step: survive, follow the bubble to the crashed ship, and look inside. There are two breakable walls; the left one has a switch behind it. Flip it to receive the Acid and the blueprint for the Globbler, the acid launcher, and to call down a cargo pod.

One older guide lists the switches as red, yellow, and blue, while the 2025 walkthrough uses magenta, cyan, and yellow. That is a naming difference in community reports, not a reason to hunt for a fourth switch.

Steam players add a useful note in a community discussion about unlocking the last three guns: the three-button puzzle is associated with “Singularity” Gravity Farms, and both regular missions and Paid Time Off can work as long as you are on the correct map. Treat that as player experience rather than a patch-note guarantee.

The Locked Bunker POI and the Red Keycard

The second answer to Mycopunk how to open bunker is the locked bunker point of interest on uncharted procedural maps. Patch 1.9 locked this POI, according to community documentation, and the red keycard is inside. There is no universal coordinate. Videos that pin one rock are describing a specific seed, not a fixed world location. Patch 1.9.4 later fixed terrain that only existed for the host, which matters if you play co-op and one player could see geometry that another could not.

The community documentation available here does not describe a three-switch sequence for this POI. The documented advice is search-based: sweep the uncharted map for the bunker and do not rely on a single screenshot. Opening it is tied to the Bunker Buster achievement. The red keycard itself is an exotic item; its in-game text describes it as a high-level Saxon security card from bunkers, and its API name is redcard.

Where to Use the Red Keycard: Flourishing Desert

The red keycard is not the key to the bunker you found it in, and it is not used on Gravity Farms. Its destination is a door in the Flourishing Desert. Using it there unlocks the Containment mission. This is the third “bunker” job in the community documentation, and it turns Mycopunk how to open bunker from a search problem into a delivery problem: find the POI, take the card, and bring it to the desert door.

What About the “Elemental Door”?

If you have seen searches for an “elemental door,” the sourced material does not tie that phrase to one specific official door. The colored switch puzzle on Gravity Farms is the closest documented mechanism. Be skeptical of claims about a fourth element puzzle unless a patch note or official source confirms it.

Bunker Buster Achievement Checklist

Bunker Buster is the achievement for opening the locked bunker. Community documentation notes that patch 2.0.1 fixed the achievement not unlocking. Players who opened a bunker before that patch should update the game and check the achievement again.

Confirm you are on an uncharted procedural map, not Gravity Farms.
Search your own seed; ignore pinned coordinates from old videos.
If you play co-op, make sure everyone is on the same updated build after the 1.9.4 terrain fix.
Open the locked POI and recheck Bunker Buster after updating to a build that includes the 2.0.1 fix.
Do not expect the red keycard to open the bunker; it is the reward inside.

FAQ

How do I open the bunker on Gravity Farms in Mycopunk?

The Mycopunk how to open bunker answer for Gravity Farms is the three-switch puzzle. Find the bunker with three inactive lights near the big ring, then flip the switches hidden behind breakable walls: one in the silo to the right, one in the green or cyan building back left, and one at the globe structure to the left. All three lights must be on.

Where do I use the red keycard in Mycopunk?

Take it to the Flourishing Desert and use it on the door that unlocks the Containment mission. It is not used on the Gravity Farms bunker or on the procedural bunker where you found it.

Is there a fixed location for the Mycopunk how to open bunker POI?

No. The locked bunker is on uncharted procedural maps, so there is no universal coordinate. Old videos that pin one rock are showing a specific seed. Search your own map.

Why did Bunker Buster not unlock after I opened the bunker?

Community documentation reports that patch 2.0.1 fixed the achievement not unlocking. Update the game and recheck the achievement if you opened a bunker before that patch.