Trailside

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 free-ride bicycle playground titled “Trailside.” Use Three.js (or an equivalent real-time 3D engine) with a soft, low-poly outdoor forest setting: a large flat muted green ground plane, a brown dirt trail, scattered stylized oak trees along both sides, pale green atmospheric fog, warm directional sunlight, soft shadows, and a calm desaturated green color palette. Use a third-person follow camera by default, positioned behind and above the rider, with an optional close first-person view.

At launch, show a dark translucent rounded menu panel in the upper-left/left side over the 3D scene. The panel should have the title “Trailside,” the subtitle “A chill bike playground — ride at your own pace,” a “CHOOSE YOUR BIKE” section, a “CHOOSE A TRAIL” section, and a bright lime-green primary button labeled “Ride this trail.” Make selection cards rounded with subtle light borders; the selected card is lime green with dark text, while unselected cards are dark translucent with light text. Offer these exact bike options and descriptions:
- “Marin Alcatraz” — “dirt jumper · short travel” (selected initially), red bike frame, dirt-jumper style, speed 8.5 and jump 9.
- “Trek Fuel EX” — “full suspension · balanced,” blue frame, full-suspension style, speed 7.4 and jump 8.
- “Trail 29er” — “29er · smooth and stable,” yellow/gold frame, 29er style, speed 7.8 and jump 8.5.
Offer these exact trail choices:
- “Downhill” — “fast lines · jumps · forest” (selected initially).
- “Pumptrack” — “flow · berms · laps.”

When the player clicks “Ride this trail,” hide the menu and show a compact translucent HUD in the upper-right containing Bike, Trail, and View values. Show a bottom overlay with the hint “WASD / arrows to ride · Shift to sprint · Space to hop · V to swap view,” plus buttons for changing the camera view and returning to the ride-selection menu. The view button should toggle between “First person” and “Third person”; keyboard V should do the same. The HUD should identify the selected bike and either “Downhill” or “Pumptrack.” There is no score, timer, health, ammunition, enemy, or win-state system: this is a relaxed ride-anywhere playground.

Build a simple rideable bike-and-rider model procedurally from meshes. The bike should include two black torus wheels, a colored metal frame, fork, seat, handlebars and grips; include a small rider with skin-colored head, shirt, and dark helmet. Change the frame color and geometry details based on the selected bike: the dirt jumper has smaller/shorter geometry, the full-suspension bike has a visible rear shock and blue styling, and the 29er has slightly larger wheels and its gold styling. Place the bike/rider at the start of the trail and have the selected visual update if the bike is changed while riding. Hide the bike model in first-person view and bring the camera very close to the rider position.

Implement physics/control behavior equivalent to a third-person character controller: WASD or arrow keys move the rider around the ground/trail, Shift enables sprinting, Space makes the rider hop/jump, gravity applies, and movement follows the selected bike’s speed and jump values. Allow free riding rather than forcing the rider along a route. Keep the camera following the rider and use a slope limit around 55 degrees.

For the Downhill trail, create a straight brown dirt strip approximately 7 units wide and 64 units long, positioned ahead of the start and with a slight yaw. Add four raised/sloped brown rectangular jump obstacles spaced down the line, alternating slightly left and right. Surround the route with the stylized oak trees visible in the forest. For the Pumptrack trail, replace the straight line with a broad brown torus-like loop laid horizontally, elongated in one direction, and add two raised semicircular berm elements on the left and right sides. The trail geometry should remain simple, clean, and low-poly, with no decorative UI beyond the selection menu, HUD, and controls described above.

Use an orthographic-feeling, polished casual-game presentation while retaining a perspective 3D camera: pale sage-green background/fog, dark forest-green ground, warm brown trail, softly lit foliage, rounded translucent charcoal UI panels, cream text, and vivid lime selection buttons. Make the layout responsive so the selection panel fits on narrow/mobile screens, and keep the canvas full-screen behind the interface.