Split Tree Surge
Puzzle
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Numbers fall. A B-tree grows below. Tap the correct leaf before it hits the bottom. Get it wrong — the tree reorganises itself. Get it right — it splits.
Split Tree Surge teaches you how a B-tree works by making you build one under pressure.
A number descends from the top of the screen trailing amber light. Below it: a glowing tree of sorted nodes, each one a rounded rectangle holding one or two keys. The player traces the path from root to leaf — is the number less than the root key? Go left. Between the two root keys? Go middle. Greater? Go right. Repeat at each level until a leaf is reached. Tap the leaf. The number slots into its sorted position with a brief gold flash.
This is the B-tree search property, felt in the hands rather than read in a textbook.
When a leaf holds two keys and a third arrives, something spectacular happens. The node blazes white. The median key launches upward trailing gold sparks. The node divides — left key and right key separating into two daughter nodes with a smooth outward motion. The median integrates into the parent with a brief bloom. New edges draw themselves. Every node adjusts position with a spring animation. The tree has reorganised itself in under a second without losing a single piece of data. This is a B-tree split. It happens every time a node overflows, and it is always correct.
When the split cascades — when the parent also overflows, and its parent above it, all the way to the root — the animations chain in sequence, each level brighter than the last. A cascade earns fifty points per level split. When the root itself splits, the entire tree descends one level, a new root appears at the top containing the single promoted key, and the screen floods with white light. Tree Grew. Plus three hundred points.
The game runs for sixty seconds. Numbers fall at a pace that allows careful tracing at first but demands faster intuition as the tree grows deeper. Three lives. A wrong tap costs one. A missed number costs one. The tree keeps building regardless — by the end of sixty seconds, a player who has understood the search property has built something with three or four levels containing dozens of sorted keys, all leaves at the same depth, all insertions correctly placed.
That guarantee — all leaves at equal depth, O(log n) search regardless of insertion order — is the reason B-trees power the storage engines of almost every major database and file system in existence. Split Tree Surge makes that guarantee visceral. The tree never becomes unbalanced because the split mechanic prevents it. The player experiences this not as a fact but as a physical property of the structure they are building.
Five level types. Bloom mode: build the tree as fast as possible in sixty seconds. Target mode: choose from available numbers to construct a specific tree structure. Cascade Hunt: find the insertion that triggers the longest chain of simultaneous splits. The same data structure. Completely different challenges.
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The developer, Gary Willson, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
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- Usage Data
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The following data may be collected but it is not linked to your identity:
- Usage Data
Accessibility
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Information
- Seller
- Gary Willson
- Size
- 4.7 MB
- Category
- Puzzle
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
- English
- Age Rating
16+
- 16+
- Copyright
- © Gary, 2026