Sky Hopper

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 portrait-friendly, full-screen Three.js-style 3D arcade game titled “Sky Hopper,” closely matching Flappy Bird. Use an orthographic camera looking straight at a side-on 2D playfield, with simple 3D geometry and lighting. Keep the visible world about 14 units wide by 18 units tall, resizing the orthographic camera to preserve the vertical framing on different aspect ratios. Render a bright sky background with a vertical gradient from sky blue at the top to very pale blue near the bottom, plus a few soft white three-lobed 3D cloud clusters in the distant background that drift slowly sideways and wrap around when offscreen. Add a strip of ground at the bottom: a broad muted golden/tan rectangular base, a green grass-colored top strip, and repeating darker tan rectangular stripes that scroll horizontally during play.

The player is a small stylized low-detail 3D bird positioned toward the left side of the screen at x=-3.2. Build it from primitives: a rounded yellow/golden oval body, a slightly darker orange/yellow flattened wing, a bright orange cone-like beak pointing right, a white spherical eye with a small dark pupil, and a small darker tail cone. The bird should bob gently up and down before the game begins. During play it is governed by vertical physics: gravity is -20, flap impulse sets vertical velocity to +7.2, and each tap/flap causes the bird to rise and then fall. Tilt the bird based on vertical velocity, clamped between about -1.2 and +0.65 radians, and animate the wing with a subtle oscillation plus a stronger flap response.

The core loop is endless survival. When play starts, spawn green pipe pairs from the right at x=10 and move them left at 4.3 units/second. Spawn another pair every 7.2/4.3 seconds (roughly 1.67 seconds), with each pair having a randomized vertical gap center between -3.8 and 4.2. Each pair consists of a wide vertical green rectangular pipe extending from near the top or bottom boundary, with a darker green cap that is slightly wider than the pipe at each end facing the gap. Pipe width is about 1.55 units and the vertical opening is 5.2 units. The playable pipe construction reaches from world y=-7.85 to y=9.5. Remove pipe pairs after they pass off the left side. The bird has collision radius about 0.52: while a pipe is horizontally near the bird, end the run if any part of the bird lies outside that pipe’s gap. Also end the run if the bird falls below y=-7.3 or rises above y=9.3, representing collision with the ground or ceiling. Do not add powerups, enemies, weapons, lives, or scrolling camera movement.

Award exactly one point when a pipe pair has fully passed the bird (when its x plus half its width is left of the bird’s x). Display the current score as a large bold white number centered at the top with a subtle dark text shadow. Persist and display a best score using local storage. At the initial state, show a centered translucent dark blue-gray rounded instruction panel with a light border and shadow: title “Sky Hopper,” instructions “Tap, click, or press space to flap.” and “Thread the gaps. Don’t hit the pipes.”, plus the best score when available. Show a small white hint near the bottom reading “Tap anywhere to start.”

Support touch/pointer tap or click anywhere in the play area and keyboard Space, W, or Up Arrow. The first flap starts the run and applies the flap impulse. While running, change the hint to “Tap or press space to flap.” On collision, stop movement/game updates, preserve the score, update the best score, and show a centered crash panel reading “Crash,” “Score: [score],” “Best: [best score],” and “Tap anywhere or use the button to restart.” Show a rounded yellow-to-orange “Play Again” button near the bottom. Tapping anywhere after game over should reset and immediately flap/start again; the button should reset, start, and flap as well. Keep the HUD mobile-safe with responsive font sizes, safe-area-aware positioning, no page scrolling, and pointer/touch interaction. Use bright, clean colors, basic Lambert/standard materials, soft lighting, and a cheerful minimal 3D style matching the supplied screenshot: blue sky, green pipes, simple bird, clouds, and tan/green ground.