Nightfall Run

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 browser-based 3D survival-horror shooter called “Nightfall Run.” Use Three.js with a low-resolution render target upscaled to the screen with nearest-neighbor pixelation, color quantization, Bayer dithering, subtle horizontal shimmer, vignette, and slight camera snapping/jitter for a PS1-era fixed-camera look. The game should open on a dark translucent menu panel titled “Nightfall Run,” with the subtitle “Survive the city. Don’t get surrounded.” Show these controls: W/S forward/back, A/D turn (tank), Shift sprint, Mouse aim, Click shoot, R reload, F flashlight, I inventory, M map, and 1 use med kit. Include a Start button and the tip “Keep moving—fog hides what’s coming.”

The playable scene is a fog-choked city at night/dusk. Build a large flat dark-gray ground plane with a subtle grid, thick gray exponential fog that severely limits visibility, and a dim blue-gray ambient light plus a weak warm dusk directional light. Make a simple city grid of streets and blocky dark buildings: buildings should be solid rectangular collision obstacles arranged in separated blocks, with dark facades, faint scattered windows, edge highlights, and grime streaks. Add a few stationary cars as street obstacles, visually represented with dark sprite-like silhouettes, windows, headlights, tires, and shadows. Place thin street-lamp poles around the streets with small pale-blue point lights that visibly flicker over time.

The player is a small dark blue humanoid/capsule character at the center of the city. Use tank controls: W moves forward in the character’s facing direction, S moves backward, A/D rotate the character, and the player collides with buildings, cars, and the world bounds. Mouse position aims independently of movement/facing, using a ray projected onto the ground; the player’s weapon direction and flashlight follow this aim direction. Hold left mouse or click to fire a handgun. Each shot launches a small bright pale-blue projectile, consumes one round, has a short fire cooldown, and produces a short synth-like shot sound. The handgun has an 18-round magazine and starts with 36 reserve rounds. Press R to reload from reserve ammunition, with messages for a full clip, no ammo, and successful reload.

Give the player 100 HP and a stamina meter starting at 100. Holding Shift while moving increases speed from roughly normal 6.2 to sprint speed 9.2, draining stamina; stamina regenerates while not sprinting. Keep the flashlight on by default: implement it as a bright white cone/spotlight from the player aimed in the mouse direction, with a limited range and strong falloff. Press F to toggle it, display a temporary “Flashlight ON/OFF” message, and dim the player fill light while it is off. The flashlight should be the main visibility tool in the fog.

Spawn zombies around the player at random angles and distances roughly 24–44 world units away, so they emerge from the fog and approach. Represent each zombie with a green zombie billboard sprite showing a humanoid body, outstretched arms, dark clothing, a green head, shadowed eyes, and a mouth scar; optionally use a faint capsule collider beneath the billboard. Zombies should continuously move toward the player, avoid/push against building collision boxes, wobble subtly, and damage the player on contact. Each zombie has 2 hit points, takes one damage per projectile hit, and disappears when killed. A contact hit removes 10 HP, briefly grants invulnerability, shakes the fixed camera, plays a low hit sound, and displays “Don’t let them grab you.”

Start each run with five zombies, then continuously spawn more while the player is alive. Increase spawn rate over time using a difficulty factor based on survival time; after the difficulty is high enough, sometimes spawn an additional zombie. Track kills and survival time. When HP reaches zero, stop gameplay and show the menu-style overlay changed to “You Died,” with text such as “Survived M:SS — Kills: N” and a “Run it back” button that resets the run. The score is represented by survival time and zombie kills in the HUD rather than a separate score display.

Occasionally drop pickups at zombie death positions: blue handgun-ammo sprite pickups, which add 12 reserve rounds, or bright green med-kit sprites with a white cross, which add one med kit. Give pickups a slight floating/rotation animation and automatically collect them when the player comes close, with temporary messages “Ammo +12” or “Med kit” and a pickup sound. Start with one med kit. Press 1 or use the Inventory overlay button to consume one med kit only while playing and only below full health; restore 45 HP up to 100 and display “Used Med Kit (+45 HP).”

Keep a minimal HUD in the upper-left/top area with pill-like readouts labeled HP, AMMO current/18, STAM, KILLS, and TIME formatted as minutes and seconds. Show temporary gameplay messages below it. Add a constantly visible square minimap in a corner with a dark transparent background, faint border, simplified building rectangles, car markers, green zombie markers, blue/green pickup markers, and a white player marker with a facing-direction line. Press M to open a larger “City Map” overlay showing the same map at a larger size; pressing M closes it. Press I to open an “Inventory” overlay listing Handgun Ammo and Med Kits, with an “Use Med Kit” button and hints for the I, 1, and M controls. While map or inventory overlays are open, block gameplay input.

Use fixed survival-horror camera rigs rather than a freely controlled camera. Define several elevated perspective camera positions covering the center, north, south, west, and east city regions; hard-cut or lightly smooth between rigs as the player crosses region bounds, always looking toward the player. Preserve the classic fixed-angle composition while allowing the mouse-ground ray to aim. Make zombies, cars, building facade art, and pickups billboard sprites that face the current camera. Use subdued blue/purple night colors, gray fog, faint warm horizon/dusk lighting, pale-blue lamp pools, bright white flashlight illumination, occasional warm window glows, minimal synth-like shot/hit/pickup sounds, and a low pulsing ambient drone. The game should be a complete playable endless survival run with no win state; the goal is to survive as long as possible without being surrounded.