Game Objective & Rules
Drop each oscillating block with exact alignment on top of the base beneath it. Construct the highest tower possible while managing accelerating block speeds, modifier rounds, and shrinking platform sizes.
Controls & Input Methods
Optimized for both high-precision desktop gaming and responsive mobile touch displays.
| Device | Input Method | Action & Description |
|---|---|---|
|
Desktop
|
Spacebar or Left Click
|
Press the spacebar or click anywhere on screen to release the moving block onto the tower base. |
|
Mobile / Tablet
|
Screen Tap
|
Tap anywhere on the screen to instantly drop the moving block. |
Core Mechanics & Difficulty Progression
Real engine mechanics confirmed by the game source code.
6.0px Perfect Alignment Threshold
When the moving block is released within 6.0 logical pixels (~2.3% of the initial 260px width) of the base below, the game registers a PERFECT drop. The block snaps flush with the base, losing zero width, and triggers harmonic synthesizer notes.
Overhang Slicing & Gravity Debris
Any alignment error exceeding 6.0 pixels slices off the overhanging portion of the block. The sliced debris tumbles downward under gravity physics, and the remaining surface width becomes the new narrower base for all future blocks.
Flow Mode & Multipliers
Chaining 5 consecutive perfect placements triggers FLOW MODE. Flow Mode lasts 8 seconds, doubles all placement scores (2x), and rewards extra timer seconds (+2s) for subsequent perfect hits.
Progressive Oscillation Speed
Block travel speed starts at a gentle 240 px/s and accelerates dynamically: 300 px/s at height 5, 360 px/s at height 10, 450 px/s at height 20, up to a maximum base cap of 620 px/s (700 px/s in Speed rounds).
Modifier Rounds (Height 15+)
Every 8 levels starting after height 15, special challenge rounds appear: Speed Round (+15% velocity), Mirror Round (reverses alternating entry direction), Blind Round (block opacity pulses), and Double Score (2x placement reward).
Scoring System & Multipliers
Scoring in STACK rewards consecutive precision placements and tall tower construction.
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Perfect Drop Base: 500 base points multiplied by your combo tier (up to 10x).
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Flow Mode Multiplier: Doubles all placement points (2x) while Flow Mode is active.
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Sliced Drop Score: Proportional points based on the percentage of surface area successfully retained.
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Height Milestones: Height milestones (10, 20, 30, 40...) trigger celebratory visual fanfare and camera adjustments.
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Game Over Condition: If a block misses the base entirely or remaining width shrinks below 5px, the tower collapses and the run ends.
Pro Tips & Proven Strategies
Tactical advice to push your session score into top global leaderboard ranks.
Focus on the Leading Edge
Rather than looking at the center of the moving block, fix your gaze on the leading front edge as it approaches the corresponding edge of the platform beneath it.
Listen for the Musical Scale Chime
Each consecutive perfect drop plays an ascending note in a harmonic musical scale, giving you immediate audio confirmation of whether your release timing was dead-on.
Use Spacebar on Desktop for Lower Latency
Tapping the physical Spacebar on a mechanical or laptop keyboard typically has lower travel latency and tactile bounce than clicking a mouse button.
Adjust Timing After an Overhang Cut
When a block gets sliced narrower, it travels across the alignment zone faster. Slightly lead your release press to compensate for the reduced overlap window.
Mobile Play & Touch Ergonomics
STACK features a vertically centered isometric camera that smoothly tracks upward as your tower rises, maintaining optimal drop visibility on both portrait and landscape mobile screens.
Global Leaderboards & Rush Locker Badges
Leaderboard metrics include Total Score, Tower Height Reached, Total Perfect Drops, and Longest Perfect Streak. Reaching tower height 25 or higher unlocks the Builder achievement badge in your Rush Locker.
Frequently Asked Questions
Common questions about gameplay mechanics, scoring, and controls.
- What is the tolerance for a Perfect drop in STACK?
- A drop qualifies as Perfect when it is aligned within 6.0 logical pixels of the block below it. Perfect drops snap flush with the platform and lose zero surface area.
- How does Flow Mode activate?
- Landing 5 consecutive perfect drops activates Flow Mode for 8 seconds, doubling placement points and granting bonus time for additional perfects.
- What happens when block edges are sliced off?
- The overhanging part of the block is sliced off by gravity physics, permanently reducing the platform width for all subsequent levels until the game ends.
- What is the minimum block width before game over?
- If your block width shrinks below 5 pixels or misses the base completely, the block drops into the void and the game ends.
- How do I unlock the Builder badge?
- Build your tower to a height of 25 blocks or higher in a single run of STACK to unlock the Builder badge in your Rush Locker.