Beat Drop

Cinevva's analyzer read this game's design doc and its source, then wrote the brief below. "Make your own" hands it to the game creator as your opening message, so you start from a real spec rather than a one-line idea.

Create a responsive browser rhythm game titled “Beat Drop” in a dark neon style. Use a full-screen canvas with a deep navy vertical gradient background (#12183b at the top fading to #070a17) and a few dim, slowly drifting blue-purple particles/stars. Center the play area in a maximum 760px-wide container with 4 equal vertical lanes, spanning from around y=150 to a glowing turquoise horizontal hit line near the bottom of the play field. Draw subtle dark translucent lane backgrounds and faint vertical dividers. The game should fit desktop and mobile screens, with safe margins and touch-friendly controls.

At the top, overlay three dark translucent rounded stat cards labeled SCORE, COMBO, and BEST, displaying score, combo as “0x”, and the persistent best score. Below them show the instruction “Stay on beat — notes land on the glowing line” during play. Initially show a prominent centered gradient button labeled “START BEAT”; pressing it starts a round. Also show the bottom hint “Keyboard: D F J K · Mobile: tap the lanes”.

The core mechanic is a four-lane falling-note rhythm game. Notes are rounded horizontal glowing rectangles, roughly 72% of a lane wide and 36px high, falling vertically from above the play field toward the turquoise hit line. Color the lanes/notes consistently: lane 1 pink (#ff5d8f), lane 2 yellow (#ffd166), lane 3 mint (#6ef3c5), and lane 4 blue (#6aa6ff). Each note has a bright soft glow and a short pale horizontal highlight in its center. Use this repeating lane sequence: 1, 2, 3, 4, 2, 3, 1, 4, then 1, 3, 2, 4, repeating. Spawn the next regular note every half second after the initial brief delay. Notes normally move at about 300 pixels/second, increasing gradually up to about 420 pixels/second over the round. Every 8 beats, also spawn an extra note in a changing lane at a faster 360 pixels/second, so the pattern becomes more demanding. The round runs for approximately 58 seconds and ends once the remaining notes have cleared.

At the bottom, place four large rounded rectangular lane buttons in a row, within the same maximum-width container, with labels 1/D, 2/F, 3/J, and 4/K. They should have dark blue translucent fills, light borders, and a pressed state that briefly turns white and shifts down slightly. On desktop, pressing D, F, J, or K triggers the corresponding lane; on mobile, tapping the corresponding button does the same. Prevent page scrolling while interacting.

When a player presses a lane, find the nearest unhit note in that lane. A hit is accepted when it is within 46 pixels of the glowing line. A precise hit within 18 pixels is “perfect” and awards 100 points; a less precise valid hit awards 60 points. Apply a combo multiplier of 1 + 0.12 times the current combo, capped at a combo value of 12 for the multiplier, then round the result and add it to the score. Increment combo and update the persistent best score. Successful hits should create a short burst of about 12 small colored particles at the line and play a brief soft synthesized musical tone; use four pitches corresponding to the lanes (C4, E4, G4, B4) if audio is available. A press with no valid nearby note resets combo to zero, gives a short incorrect-hit tone, and briefly flashes the background pink. Notes that pass more than 65 pixels beyond the line without being hit are marked missed and reset combo to zero. Hit notes should disappear.

When the approximately 58-second round finishes, stop gameplay and show a centered modal overlay with a blurred/dimmed background. The modal is a dark rounded card saying “Beat complete”, showing “Score [score] · Best [best]”, and a “PLAY AGAIN” button that resets score, combo, time, beat sequence, notes, and particles and starts a new round. Store the best score in local browser storage so it survives reloads. Pressing Enter when not playing should also start a round. Keep the visual presentation clean, centered, neon, and arcade-like, with no extra gameplay systems beyond score, combo, best score, falling notes, timing judgments, particles, sound, and the end-of-round replay flow.