Marble Sort Level 731 presents a split board with a serious bottleneck: a crate on the left hides the only key to the right side's bottom lock. Your priority is to open that crate early and avoid crowding the conveyor with useless colors.
The top tray separates into two parts. On the left, a dense pile includes a bottom row of Dark Blue, Yellow, Green, Pink, and Red, topped by many layers of White, Green, Light Blue, and Purple. The crate sits at the top right of this pile. On the right, a Purple lock holds two Orange boxes; below them, a Light Blue box carries a Purple key, and a gold lock secures a Purple box at the very bottom, but no gold key is visible.
Marble Sort Level 731 Walkthrough
The lower boxes request Light Green and Light Blue from the start, then White, Pink, and Purple later. The conveyor is small, so wrong drops cause immediate failure.
The hidden gold key inside the crate is the sole blocker; without it, you cannot free the bottom-right Purple box.
How to Beat Marble Sort Level 731 — Step-by-Step
Phase one: Feed the bottom and grab the visible key
- Tap the Light Green marbles on the left to feed the first lower box.
- Drop the Light Blue box from the right side to collect the Purple key, shattering the top lock and releasing the two Orange boxes—do not tap them yet.
- Send White, Purple, and the remaining Light Blue from the left side as lower boxes appear.
- Focus only on clearing boxes touching the crate; ignore Dark Blue, Yellow, Pink, and Red at the left bottom unless the conveyor needs them.
Phase two: Open the crate and unlock the right
- Once the crate's surroundings are gone, it opens to reveal a White box, a Green box, and a Red box carrying the gold key.
- Clear matching lower boxes until Red is accepted, then drop the Red box onto the conveyor.
- This breaks the gold lock, freeing the Purple box on the right.
- Now that many colors are open, check the lower boxes and only send matching colors to avoid jamming.
Phase three: Clear the open board
- Drop the freed Orange and Purple boxes from the right as soon as lower boxes match.
- Release the bottom-left cluster (Dark Blue, Yellow, Pink, Green) systematically, waiting for each color's box.
- Finish with the last Red and Pink marbles to empty the conveyor.
Tips & tricks
- Keep the conveyor as empty as possible; never send a color unless a matching lower box is visible.
- Prioritize the crate over the right side's tempting Purple key—the key you see is a decoy.
- Use the two Orange boxes as buffers; they can be held to match later.
Common mistakes
- Dropping colors from the right side too early clogs the conveyor before the crate opens.
- Ignoring the lower boxes' order and sending random colors causes instant loss.
- Forgetting that the gold key is hidden in the crate, so you waste moves searching for it elsewhere.
Marble Sort Level 731 FAQ
Why does my Conveyor Belt flood on Marble Sort Level 731?
Because you drop right-side colors before unlocking the crate, filling the belt with colors that have no matching lower box yet.
Which color do I clear first on Marble Sort Level 731?
Clear Light Green and Light Blue first to feed the initial lower boxes, then work on the left crate.
How many moves does it take to clear Marble Sort Level 731?
It varies, but a precise sequence takes around 40 to 50 moves if you avoid mistakes.
Do I need boosters to beat Marble Sort Level 731?
No, boosters are not required if you follow the correct order and manage the conveyor carefully.
What happens if I drop the right-side Orange boxes early on Marble Sort Level 731?
You'll jam the conveyor with Orange before the lower boxes are ready, likely causing a loss within a few moves.
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