Complete Level 421 by reading the numbered ball-container colors, matching colored light to three flower shapes, activating the lighthouses in the giant ball pit and scoring in all four hoops. Finishing the hoop room opens the route toward Overgrowth.
The colors assigned to the containers and flower shapes can differ between runs. Solve from the clues you see rather than using a fixed list of colors or a petal-count answer from another playthrough. Level 421 was added in the August 2026 update, so older routes that go straight from the Bunker to Overgrowth omit this level.
Enter from the Bunker branch
After reaching the later Hub and Bunker progression, look for the branch with plastic balls around its entrance. This is the route that previously connected directly toward Overgrowth. Follow the accessible card-controlled route down into the M.E.G. area and prepare for the color puzzle.
The opening rooms contain supplies and notes. Take time to read the color-mixing sheet before entering an answer. It teaches a rule used in both the first gate and the later flower projectors.
Do not search the early story levels for an ordinary door labeled 421. This branch belongs to later progression and is reached through the Bunker route, not by counting sequential level numbers.
Read the four numbered containers
The first locked gate uses the colors in four numbered containers. Three have a single ball color; one contains two colors that must be combined using the sheet.
- Inspect each container's number.
- Record the visible ball color for each single-color container.
- For the two-color container, use the mixing sheet to determine the resulting color.
- Enter the resulting sequence at the terminal in container-number order.
- Confirm the gate opens before proceeding.
The two-color container contributes one combined answer, not two separate entries. For example, the clue sheet's blue-and-red combination produces pink. Use the displayed combination rules for the actual pair in your run.
Container position and container number are also different references. If you walk around the room from another side, the closest container is not necessarily the first code entry. Read the labels rather than ordering them by the direction you happened to search.
Record flower shape and color together
Beyond the first gate, explore the rooms for three painted flowers. Each has a recognizable shape and a color. You need the pairing between those two properties, so record more than “I found a pink room.”
The relevant colors are pink, cyan and yellow, with the assignment to the flower types changing between playthroughs. A flower's petal pattern helps you recognize the corresponding uncolored drawing later, but the same pattern is not a permanent password for one particular color.
Keep the pairings separate in co-op reports. “This flower shape is cyan” carries more information than several teammates independently calling out a color without identifying its drawing. If you are unsure which shape a teammate means, inspect the drawing rather than converting a guess into the projector solution.
Scratchers roam the search area. Crouch to keep the approach controlled and locate tables or gurneys you can hide under if a pursuit begins. Do not stand in the hallway studying a flower while ignoring the sound of an approaching entity.
Color the matching drawings with projectors
The locked ball-pit area is on the upper floor, with projector rooms around it. Inspect the note near the entrance and match the white flower drawings to the colored versions you found while exploring.
Use each projector's buttons to produce the required color on its matching flower. The same mixing logic from the container room applies. You are matching the shape-and-color pair, rather than arranging three projectors in the order you found the flowers.
If the gate remains locked, check each drawing against your record. A visually plausible color is not enough if it belongs to another flower shape. Confirm that all three flower puzzles have been set correctly.
A teammate watching the corridor can help the solving player respond to Scratchers, but the puzzle area should not be treated as permanently safe. Stop the interaction and hide if necessary, then return to the specific drawing you still need to finish.
When the gate opens, enter the accessible ball-pit room and use its no-clip transition to reach Plastic Mariana itself.
Activate the lighthouses without rushing the shark
The next space is a huge ball pit with lighthouses and a giant shark moving through the balls. Activate the lighthouse lights while keeping track of the shark's fin and using the available safe positions between crossings.
Before stepping into the balls, locate the fin and choose the next place you are trying to reach. Moving with a destination lets you evaluate the crossing. Wandering into the pit while looking for the next tower leaves you trying to navigate and react to the shark simultaneously.
Do not run toward the fin or try to leave by walking indefinitely into the edge of the area. The boundary is dangerous to your sanity; it is not an alternative exit. The required route is created by the lighthouse objective.
Continue until all the lighthouse lights have been activated. If the exit cue has not appeared, check the switches rather than assuming a single lit tower completes the area.
Follow the white balls to the transition
Once the lights are on, watch for the white balls that form the route through the pit. Follow their movement until they indicate the circle or gathering point where you can drop through to the next room.
This visual cue is more useful than a remembered compass direction. The level is asking you to recognize the changed balls after completing the switches. Randomly jumping into ordinary portions of the pit does not replace that objective.
Keep watching for the shark while reaching the indicated point. Activating the lights solves the exit condition; it does not mean that you should stop considering the entity on the way there.
Score in each of the four hoops
The last room has four hoops. Pick up plastic balls from the floor and make a successful shot into each one. You can throw from directly in front of a hoop and jump for a close shot, or use a bounce off the nearby surface to adjust the approach.
There is no requirement to carry every ball from the earlier search rooms. If you arrived without any, collect the balls available here. Keep track of which hoops you have completed so you do not repeatedly shoot at the same one while another remains unused.
When all four hoops are satisfied, the nearby door opens. Continue through it toward the Death Slides and Overgrowth progression.
The October 29 update fixed several Plastic Mariana problems, including ball clipping and a shark that could stop pursuing players after a kill. Do not build your route around those old behaviors. The intended solution remains the color puzzles, lighthouse objective, white-ball transition and all four hoops.