🎹 Neon Tiles — Oh! Susanna

A neon-styled 4-lane rhythm game built around Stephen Foster's 1848 American classic "Oh! Susanna" — "I come from Alabama with a banjo on my knee..." Tap the falling tiles in time, hold them down for sustained notes, and chain together 16th-note pairs across both hands. Cyberpunk visuals with a cyan→magenta gradient palette and the Orbitron typeface give it a retro-futuristic arcade feel.

🎮 How to Play

• Tap / Click — Tap tiles on mobile, or click them with the mouse on desktop.
• Keyboard — Use A S D F for the four lanes (left → right).
• Hold notes — For taller tiles, keep the key/finger pressed until the tile clears.
• 16th-note pairs — Two tiles spawn on the same row in different lanes; tap both, in either order.
• Pause — Space or P
• Mute / Unmute — M
• Quick start / restart — Press D while any overlay is showing.

✨ Features

🎵 Real Melody, Real Pitch

• Plays through all six phrases of "Oh! Susanna" per cycle, in C major:
  • Verse 1 — "I come from Alabama with a banjo on my knee"
  • Verse 2 — "I'm goin' to Louisiana, my true love for to see"
  • Verse 3 / 4 — verse repeats with the cadence extended on the final word
  • Chorus — "Oh! Susanna, oh don't you cry for me"
  • Final line — verse 2 reprise to close out the cycle
• Mix of 8th-note tap tiles, multi-beat hold tiles (quarter notes and a dotted-quarter cadence), and 16th-note pair tiles that straddle both hands.
• Each note plays at its actual pitch (C4 / D4 / E4 / F4 / G4 / A4) — you're literally performing the song, not hitting random tones.
• Hold tiles produce a sustained tone that rings until you release; taps use crisp gated envelopes.

👯 16th-Note Pair Tiles

• Pair tiles spawn as two tiles on the same row in non-adjacent lanes (A+D or S+F), forcing you to use both hands.
• The pair's two pitches play in score order regardless of which tile you hit first — so the melody stays correct whether you lead with your left or right.
• Pair lanes are remembered so the very next single tile won't land on either of them, keeping flow smooth.

🚀 Progressive Difficulty

• BPM increases by +12.5% each cycle (60 → 67.5 → 75 → 82.5...) — a gentler ramp than typical rhythm games, giving you a longer runway through the harder later cycles.
• The melody is also transposed up by a whole step (2 semitones) every cycle, raising the key as the tempo climbs — fresh tonal challenge on each loop.

💢 Visible Miss Feedback

• Tap on empty space or hit the wrong tile and you'll see a red flash at the tap point (and on the wrong tile, if any), held on screen for 450 ms.
• Plays a short dissonant low buzz with downward portamento so misses are clearly audible too.
• The game ends after the miss display, giving you a clear "what just happened" beat instead of a silent cut to game over.

🎨 Polished Neon Visuals

• Hand-tuned per-lane colors along a cyan → blue → purple → magenta gradient that matches the logo.
• Glowing tube borders, soft outer halos, and scanline textures only inside the active press zone so the tappable area is instantly readable on hold tiles.
• Animated "neon tile" START button that physically slides down the board into the game on press — no jarring screen transitions. Same treatment on the PLAY AGAIN button.
• Score-burst flash animation on every successful hit.

🧠 Smart Lane Distribution

• Lanes are picked dynamically rather than randomly: the algorithm avoids consecutive same-lane spawns and balances left vs. right side usage, so the gameplay always feels fair and varied.
• Pair tiles automatically pick non-adjacent lanes for a balanced two-handed layout.

🎯 Forgiving Hold Timing

• Hold tiles only require 75% of the full duration — releasing slightly early still counts. This was a deliberate choice to reward feel over frame-perfect precision.
• The hold-progress fill uses a soft gradient fade at its top edge instead of a hard line, so there's no visible pass/fail boundary to fixate on.

🎼 Scoring

• 10 points per beat cleared (so a 2-beat hold = 20, a dotted-quarter hold = 30).
• High score saved locally via localStorage and shown on the start and game-over screens.

📱 Mobile-First Input

• Multi-touch support — different fingers on different lanes are tracked independently via touch.identifier, which is essential for the 16th-note pair tiles.
• Coordinate-based hit testing rather than lane-only, so taps register exactly where your finger lands.
• touch-action: none and user-scalable=no to prevent scrolling/zooming during play.
• Viewport sized in vw units (9:16 portrait, 177.78vw tall) so it scales perfectly across phone screens.
• Mouse-up listener attached to window so releases register even if the cursor leaves the canvas.

🛠️ Tech Stack

• Pure HTML / CSS / JavaScript — zero dependencies, zero build