Marble Sort Level 391 Walkthrough & Solution

Level 391 Board Overview: The Mystery-Target Tray

Level 391 plays out on the block-grid variant: a compact tray of columns feeding four receiver slots at the top, with a conveyor belt at the bottom that never stops delivering. The level opens with a serious planning problem — the receiver slots show grey ’?’ mystery tiles instead of clean color requests, and a handful of ’?’ tiles sit on the grid itself. You start the solve without a reliable target list.

What you can see is the tray inventory. Blue, Purple, Green, and Pink tiles stand in the middle stacks, with Yellow, Brown, Orange, and Teal scattered around the edges and lower rows, and several cells already empty. The belt below is stocked in sequence — Green, Pink, Purple, Teal, Orange, then Blue — so the front of the queue gives you a preview of what the grid will keep receiving.

One tile stands out from the rest: a special numbered block marked ‘3’ sitting in the tray. It pays out like several tiles at once, so it is the single most valuable piece on the opening board. The rest of the level is a waiting game — reveal the mystery targets, feed the colors they ask for, and let the conveyor cycle the decoys past.

The Trap in Marble Sort Level 391

The board is rigged to make you feed before you can see the target list. Here is the layout:

• The receiver row starts under ’?’ tiles: the top slots display mystery tiles instead of color requests, so the only safe early drops are the colors you can already match against a revealed slot. Never assume a target you have not seen.
• Mystery ’?’ tiles sit on the grid too: a few columns are capped with unknowns, which means part of the tray cannot be planned until you interact with it.
• The conveyor feeds by itself: Green, Pink, Purple, Teal, Orange, and Blue arrive in an endless loop, so the belt fills with colors whether or not their slots are open. Tap greedily and the queue jams.
• The numbered ‘3’ block is easy to waste: it counts as several tiles in one drop, so releasing it into a slot that is not ready burns the best tool on the board.

Marble Sort Level 391 Step-by-Step Walkthrough

Reveal the targets before you commit to a plan. Follow the release order.

Opening: reveal the receivers, bank the 3-block

1. Start by feeding the colors you can positively match — Blue, Purple, and Green are visible in the tray, and their drops confirm which mystery slot wants them.
2. Treat every ’?’ tile as an unknown: when a reveal matches an open slot, drop it; otherwise leave the column and come back.
3. Bank the numbered ‘3’ block as soon as a matching slot sits in the front row — one release pays several tiles at once and clears serious tray space.
4. Watch the belt’s opening run: Green, Pink, Purple, Teal, Orange, then Blue. Only tap a queued color whose slot is actually open.
5. Keep the visible Yellow, Brown, and Orange tiles parked for now — they have no confirmed slot in the opening, so they are bait.

Midgame: close Blue, Purple, and Pink

By the middle of the solve the mystery covers have lifted and the tray has thinned out. Three of the four receiver slots are banked with their colors — Blue, Purple, and Pink — while the remaining grid holds Green, Red, and Orange stacks plus a couple of lingering ’?’ tiles. The belt is now cycling Purple, Brown, Dark Green, Red, Blue, and Green with Light Blue tiles mixed in.

6. Feed Blue, Purple, and Pink tiles into their open slots whenever they surface — these three colors finish first and clear most of the early pressure.
7. Work each remaining stack one tile at a time; the buried tiles under the Green and Red layers are what the last slot needs.
8. Let the conveyor cycle the decoys: Brown, Dark Green, Orange, and Yellow ride past without a home, so do not force them onto the grid.
9. When a Light Blue tile appears in the queue, treat it as precious — it is the color the final open slot is waiting for.
10. Prioritize columns that expose two matching tiles in a row; clearing them empties a column and opens the tray for the endgame.

Cleanup: feed the last slot

With three receivers closed, the level narrows to a single-color finish. The last open slot takes Light Blue, and the final capture shows the tray stripped down to a few single tiles with the belt still cycling greens, purples, dark blues, and browns behind them — the board is still in play when the footage cuts, with the last target just about to bank.

11. Play only to the final Light Blue slot from here — every other color on the belt or the grid is a decoy.
12. Let the queue cycle through its batches; Light Blue tiles arrive one at a time, so feed them as they come and ignore everything else.
13. Clear the last Green, Red, and Orange stragglers only when they block a Light Blue tile from reaching the slot.
14. Finish the last slot as the final Light Blue tiles drop and let the tray empty. The level completes the moment the last tile lands.

Level 391 Tips Recap

• Reveal before you commit: the receiver row starts under ’?’ tiles, so never plan a combo on a target you have not seen.
• Bank the numbered ‘3’ block against an open slot — it pays several tiles in a single drop.
• Only feed colors with an open slot; the conveyor keeps cycling decoys, so let unneeded batches ride instead of forcing them.
• In the endgame everything funnels into the last Light Blue slot — cycle the belt and feed the singles as they arrive.