Skyline Sprint

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/mobile-friendly 2D endless runner titled “Skyline Sprint.” Render the gameplay on a full-screen HTML canvas with a fixed HUD layered above it. The character automatically runs forward while remaining near the left side of the screen; the world, obstacles, coins, skyline, and road markings move from right to left. The player’s goal is to survive as long as possible, increase the score over time, collect gold coins, and achieve the highest score.

Core gameplay: begin on a polished main menu with the title “Run the Skyline,” subtitle “Leap rooftops, dodge drones, collect gold, and upgrade your runner,” a prominent “Start Run” button, an “Open Shop” button, and a clearly visible orange/gold “Support Creator / Tip” button. Starting a run resets the score and active objects. During a run, score increases continuously at 10 points per second, movement speed starts around 360 and increases with score up to about 680, making the run progressively faster. Display the current score at the top right and the persistent coin wallet beside it. When the player collides with an obstacle, end the run and show a “Run Over” panel with the final score, “Run Again,” and “Visit Shop.”

Player and controls: draw a small glowing rounded-rectangle runner in cyan/light blue with a dark eye/visor detail, pink accent near the feet, white highlight, and a cyan motion-trail echo behind it. The runner is affected by gravity and can jump only while grounded. On desktop, Space, Arrow Up, or W jumps; Arrow Down or S activates a slide while held. On mobile, tapping the upper/main screen jumps, and provide large bottom touch buttons: a down-arrow slide button at bottom left and an up-arrow jump button at bottom right. Sliding temporarily shortens the player hitbox from roughly 58px high to 34px high, allowing low hazards to be avoided; restore the normal height when released. A jump uses a strong upward impulse, gravity, and visible landing/jump particle bursts. If the Sky Boots upgrade is owned, the jump is higher.

Obstacles: spawn continuously from the right and move left at the current game speed. Use two visual/hitbox types: orange glowing ground blocks, approximately 30–52px wide and 42–64px high, positioned on the ground; and pink glowing flying drones, about 50px wide and 24px high, positioned above the ground so the player must jump or otherwise avoid them. Use simple rounded neon shapes, not detailed sprites. Collision ends the run and creates a pink particle burst.

Collectibles: spawn gold coins from the right at varied heights above the ground. Draw them as bright gold circular coins with glow, a pale vertical center mark, and a subtle spinning/elliptical animation. Picking one up increases the score by 35, adds one to the persistent coin wallet, and creates gold particles. Use a normal pickup radius of about 32px; if the Coin Magnet upgrade is owned, increase it to about 58px.

Shop and persistence: keep the collected coin wallet and upgrade ownership in local storage so they persist between runs and page reloads. The shop is accessible from the main menu and game-over menu, but not while a run is active. Style it as a translucent rounded panel titled “Runner Shop” with the subtitle “Spend your collected coins on permanent upgrades.” Include these exact upgrade cards and one-time prices: “Coin Magnet” — “Collect coins from farther away.” — 100 coins; “Sky Boots” — “Jump higher and clear drones.” — 150 coins; and “Gold Trail” — “Give your runner a richer trail.” — 250 coins. Purchased upgrades remain owned; prevent repurchasing and show an already-owned state/message, and reject purchases when the player lacks coins. Coin Magnet changes pickup range, Sky Boots changes jump strength, and Gold Trail changes the runner’s trail color from cyan to gold. Also include a “Coin Pack” card with “Demo pack placeholder for Stripe checkout” and a “Buy Coin Pack” button.

Stripe support: include “Support Creator / Tip” buttons on the main menu and in the shop, plus the coin-pack checkout button. They should open a configurable external Stripe Payment Link in a new tab. Use a clearly marked placeholder configuration such as STRIPE_URL = “PASTE_YOUR_STRIPE_PAYMENT_LINK_HERE”; if it has not been replaced with an http(s) link, show a helpful message telling the creator to add the Stripe Payment Link. Do not claim that payment processing is implemented beyond this external-link behavior.

Visual direction: use a neon, futuristic night-city aesthetic. Paint a vertical gradient sky from very dark navy at the top through deep blue and purple to pink near the horizon. Add many small twinkling blue-white stars, a pale yellow moon with a large soft circular glow in the upper-right, faint horizontal speed lines, and two parallax layers of dark purple/blue building silhouettes with occasional dim lit windows. The ground should be a nearly black road/platform beginning just below the runner, with a thin cool-blue edge line and repeating muted blue lane dashes. Add a subtle dark vignette and faint horizontal scanline texture over the scene. Use translucent, blurred dark navy panels with thin blue-violet borders, rounded corners, soft shadows, and gradient buttons (cyan to lavender for primary actions; gold/orange for support actions). Use bold uppercase tracking for the small “SKYLINE SPRINT” brand, large gradient headline typography, and clear score/wallet typography. Keep the entire experience responsive to portrait phone screens and desktop keyboard play, hide menu panels while playing, and keep the touch controls visible at the bottom.