Stack Tower

One tap drops a sliding floor onto your skyscraper. Overhangs are sliced off and the tower narrows; perfect drops keep the full width. Climb from golden hour into the night sky.

Stack Tower

One tap, one floor. A new floor slides back and forth above your skyscraper, and you decide when it drops. Whatever hangs over the edge of the floor below is sliced off and tumbles away, so the next floor is narrower. Land it dead centre and it snaps into place at full width.

Build from golden hour into the night sky. The tower ends the moment a floor misses completely.

How to play

1. Pick a difficulty and press Start building.
2. Tap or click anywhere on the play area, or press Space or ↓, to drop the sliding floor.
3. The part that lands on the floor below stays. The overhang is cut off and falls.
4. The next floor is exactly as wide as what you kept, and it moves a little faster.
5. A floor that misses the tower completely ends the run.

Perfect drops

If a floor lands within the perfect window of the centre, it snaps into place and keeps the full width. A row of perfect drops also wins width back: every few perfect drops in a row widen the tower, up to the starting width of 180 units. Each perfect drop in a row rings a higher note.

Difficulty

Normal, Hard

Starting speed, 150 units/s, 210 units/s

Speed-up, +5 per floor until 330, then +1.5 per floor, +7 per floor until 420, then +2 per floor

Perfect window, ±7 units, ±4 units

Widening, 4 perfect drops in a row: +12 units, 5 perfect drops in a row: +8 units

Where floors come from, Always the left, Left and right in turn

Swinging floors, None, Every third floor: slow at the ends, fastest in the middle

Points, ×1, ×1.5

The tower starts 180 units wide and each floor sweeps 200 units to each side of the floor below. The speed of every floor is fixed by the difficulty, so every player faces exactly the same climb. The speed never stops rising, so every tower ends sooner or later.

Score

• 10 points for every floor, 5 more for every perfect drop and 10 more each time the tower widens.
• On Hard the total is multiplied by 1.5 and rounded.
• Normal and Hard have separate leaderboards. Higher is better.
• The result screen shows your floors, perfect drops, best streak and the code of your skyline. The

skyline code only names the colours and city of that run; it never changes the timing.

Controls

Action, Mouse and touch, Keyboard

Drop the floor, Tap or click the play area, Space or ↓

Pause, Pause button, Esc or P

The game pauses when its window loses focus. Sound, reduced motion and the interface language (English, Korean, Japanese, Chinese) can be changed at the top of the game.

Tips

Every floor reaches the centre after the same quarter of its sweep, so find the rhythm instead of chasing the floor with your eyes. The dashed guides above the top floor show its edges. A narrow tower is not lost: a few perfect drops in a row win the width back.