Long Grey Cave

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 first-person exploration game titled “Long Grey Cave” using Three.js ES modules and GLTFLoader. The player starts inside a long, dark grey rocky tunnel at approximately (0, 0, 7.5), looking down the cave. The cave runs roughly 168 world units forward along the negative Z axis and gently curves: its center shifts procedurally along the route and its walkable width varies around 3.2 units. Build the floor, side walls, low ceiling, occasional jutting rock ribs, and scattered loose rocks from cave/cliff rock assets, arranged in repeated sections down the full tunnel. Apply a subtle procedurally generated grey rock texture with noisy speckles and fine crack-like strokes to the cave materials; use dark grey, highly rough, non-metallic materials. Keep the environment sparse, oppressive, and mostly UI-free.

Use a perspective first-person camera with about a 74-degree field of view. The camera is positioned at player eye height around 1.65 units above the floor, with mouse-look yaw and pitch; clamp pitch just short of looking fully straight up or down. Use a very dark blue-black background and exponential fog so distant parts of the cave fade into darkness. Light the cave with dim cool grey ambient/hemisphere light, a weak cool entrance light, a faint directional fill, and sparse cool point lights spaced down the tunnel. Enable antialiasing, capped device pixel ratio, soft shadows, ACES filmic tone mapping, and low exposure for the dark cinematic appearance.

The core loop is simply walking forward through the cave, looking around, jumping over uneven rock patches, finding a fallen skeleton, collecting its torch, and continuing toward the far end. Place a fallen skeleton around z = -32, slightly to one side of the cave center, using a fallen bones/ribs model and a skull model lying on the ground. It holds a lit torch asset angled near its body. Add a warm orange point light at the skeleton torch so it is a visible focal point in the otherwise cool cave. When the player walks within about 1.85 units of this pickup, automatically collect it: hide the torch model and its skeleton torch light, and strengthen the player’s attached light, changing it from a weak cool sight light to a brighter warm orange torch light positioned slightly forward and down from the camera. Increase the torch light range to about 17 units, reduce fog density slightly, and raise exposure modestly after pickup. Before pickup, still provide a weak cool player light so nearby geometry is visible.

At the far end, around z = -164, place a large heavy dark dungeon gate/door asset centered in the tunnel, with a dim cool light near it. The door is an end landmark; do not add combat, enemies, inventory screens, dialogue, or a door-opening sequence unless explicitly implemented separately—the source mechanics only place the door and allow the player to reach it.

Controls: WASD and arrow keys move relative to the camera yaw; W/Up moves forward and S/Down backward, A/Left and D/Right strafe. Normal movement is about 4.2 units/second. Holding Shift while moving and while grounded enables sprint at about 7 units/second. Sprint stamina starts at 100, drains at 34 per second, and regenerates at 18 per second when not sprinting; sprinting stops when stamina is nearly empty. Space jumps with an initial vertical speed around 5.8 and gravity around 18, with reduced horizontal air control (about 55%); the player lands automatically on the cave floor. Keep the player constrained to the curved tunnel’s walkable width and between the entrance and far endpoint. On desktop, clicking the canvas requests pointer lock and mouse movement controls look. On touch devices, dragging on the canvas controls look. Make the canvas fill the viewport with no scrolling, browser selection, or visible gameplay HUD. The visual result should be a quiet, dark, long grey rocky cave walk with cool shadows, sparse rock detail, and a strong warm torch discovery moment.