Skeleton Duel

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.

Recreate a portrait-friendly fullscreen rhythm game titled "Skeleton Duel". Use a single responsive HTML canvas filling the viewport, with a fixed HUD over it. The visual setting is a dark, nearly black/navy cavern-like duel arena: draw a subtle radial blue-gray glow behind the upper center, faint scattered square stars/dust, and a dark jagged ground silhouette across the middle/lower background. At the top HUD, show the gold uppercase brand "SKELETON DUEL" on the left. On the right show compact dark translucent chips labeled SCORE, COMBO, and HP, with live values; HP is displayed as a percentage beginning at 100%. Center an illustrated cartoon skeleton opponent in the upper portion of the screen: a cream skull with large black oval eye sockets and tiny red highlights, a simple black curved mouth, a cream ribcage, and black stick-like limbs. Add the character name Frostbite and dialogue text in the lower-middle area, initially: "heh... let's see if you can keep up." When a round begins, change it to "show me your rhythm, human." Use a blinking cursor-like vertical mark after dialogue text. At the end, show either "the rhythm fades... try again." after HP reaches zero or "not bad. you survived the duel." after all notes have been resolved.

The core gameplay is a four-lane arrow rhythm duel. Center four narrow vertical lanes in the lower half of the canvas, separated by small gaps, with faint translucent fills and outlines. Their bottoms terminate at a bright horizontal judgment line positioned near the bottom, leaving room below for four large touch buttons. The four lanes map left to right to left arrow, down arrow, up arrow, right arrow. Spawn a fixed chart of 72 musical note events, beginning about 2.1 seconds after starting. Use a tempo of 132 BPM and make notes travel from the upper part of each lane down toward the judgment line over about 1.7 seconds. Include single notes and occasional simultaneous chords, cycling through these lane patterns: [0], [1], [2], [3], [0,2], [1,3], [0,3], [1,2], [0,1,3], [0,2,3], [1], [2], [3], [0,3]. Advance event timing by 0.72 beats normally, and by 1.25 beats after every eighth event. Notes should be bright, glowing, chunky upward-pointing arrows, color-coded by lane: lane 0 cyan-blue (#69d7ff), lane 1 yellow (#ffd34d), lane 2 pink (#ff7fb5), and lane 3 mint green (#8ff08a). Draw faint stationary target arrows at the judgment line in the same four colors. Notes visibly move downward toward the line.

The player can press keyboard ArrowLeft, ArrowDown, ArrowUp, and ArrowRight, or tap the four on-screen buttons. Trigger only once per key press rather than repeatedly while held. A note is judged against the nearest unresolved note in that lane when the input occurs, with a hit window of 0.17 seconds on either side of its scheduled time. Award PERFECT for the tightest inner portion of the window (distance/window ratio below 0.27), GREAT for the next portion (below 0.55), otherwise GOOD. Award respectively 350, 200, or 100 base points, plus 6 times the current combo; increment combo on a successful hit and update the best combo in local storage. A successful hit creates a burst of 14 small colored square particles at the lane's judgment point, and briefly displays the judgment word above the line in its judgment color. If the player presses a lane with no note in range, reset combo, subtract 5 HP, briefly shake the screen, and show a red MISS. Automatically mark notes missed once they are more than 0.17 seconds late, reset combo, subtract 4 HP, and show red MISS. Clamp displayed HP to zero. End the duel when HP is zero, or when every note is hit or missed. On game over/completion, stop the chart and show a prominent button at the center reading RETRY or PLAY AGAIN; clicking it resets score, combo, HP, and the chart.

At the bottom overlay, provide four large square dark buttons with subtle borders and black offset shadows, labeled visually with ←, ↓, ↑, →, matching the lane order; buttons should depress briefly on touch/click. Use responsive sizing: compact buttons on mobile and roughly 72px buttons on larger screens. Keep the pixel-clean arcade UI in a Trebuchet/system sans-serif style, with cream text, gold highlights, cyan accents, red damage feedback, glow effects on arrows and the judgment line, and small screen shake on incorrect manual inputs. Include a simple BEGIN DUEL start button centered around 53% viewport height before play starts; allow Space to start as well. Persist the best combo under a local-storage key and display the live score, combo, and HP throughout.