Diamond Derby

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 mobile-friendly 3D arcade baseball home run derby called “Diamond Derby.” Use a behind-the-batter, slightly elevated perspective camera looking from home plate down a bright daytime baseball field toward the pitcher and outfield. Render a stylized low-detail stadium in Three.js or an equivalent 3D engine: a large green grass bowl, a brown dirt/home-plate area, white foul lines extending into the outfield, a brown warning-track ring, a curved dark blue outfield fence, and simple stacked blue-gray crowd/bleacher blocks beyond the fence. Light the scene with soft ambient daylight and a strong directional sun, with a pale blue sky/fog background. Place a simple blocky batter in the foreground on the right side of home plate: navy uniform torso, white hips/pants and legs, dark shoes, tan spherical head and arms, navy helmet, and a tan bat. Include a simple rectangular pitcher model in a light uniform with a navy cap on the mound in the distance. The batter’s bat and arms should animate through a quick visible swing when the player presses swing; otherwise hold a ready batting pose. Keep the camera aimed toward the field and subtly track/shift based on the ball and aim direction.

Core gameplay is exactly a 10-pitch home run derby. Start on an instructional dark translucent overlay card titled “Diamond Derby,” explaining: baseball home run derby, press/tap SWING as the pitch reaches the plate, use Left/Right or A/D to pull the ball, and hit as many home runs as possible in 10 pitches. A Start Derby button begins play; after all pitches, show the overlay again with the final result and a Play Again button. The keyboard Space key starts the game from the intro/game-over screen and swings during play. On touch/mobile, provide three large bottom controls: blue left arrow, orange-red SWING button, and blue right arrow. Make them rounded, high-contrast, pressable buttons.

At the top HUD, show a dark translucent rounded panel labeled “DERBY SCORE” with a value such as “0 HR,” a right-side panel labeled “PITCHES LEFT” showing 10, and a “CALL” panel containing the current gameplay instruction/result. Above the controls, show a pill reading “Aim: Center.” Aim has five discrete positions: Pull, Left Center, Center, Right Center, and Oppo. Left/A and right/D move one step through these positions; the arrow buttons do the same. Update the batter’s stance/rotation slightly and move a yellow ground aim ring in the outfield as aim changes.

Gameplay timing and physics: after starting, wait briefly, then repeatedly throw a white baseball from the pitcher at approximately y=2.15, z=-18 toward home plate at z=0, with slight random horizontal and vertical variation. The player must swing while the ball is near the plate, within about 1.25 world units in depth, x within about 1.05 of the contact point, and y between 0.8 and 3.7. Swinging early or outside this zone produces a miss/too-early message and does not hit the ball. A valid hit launches the ball forward toward the outfield with velocity based on timing: better timing gives more power and loft. Add aim-dependent horizontal velocity so left/right aim pulls the ball toward different field directions. Apply gravity so the hit ball follows an obvious arc and bounces/lands on the field.

When a hit ball reaches at least 70 world units from home plate, is beyond z=20, remains in fair territory, and is above y=3.5 while crossing the curved fence, award exactly one home run and increment the score. Show feedback such as “HOME RUN! That one cleared the wall,” “Barreled. Stay fair…,” “Solid contact — carry!,” or “Got under it a bit. Might stay in the park.” If the ball lands without clearing the fence, decrement the pitches remaining and report an in-play, warning-track, or foul result as appropriate; a pitch that passes home plate or drops before contact also decrements the remaining pitches. Queue the next pitch after a short delay. Never allow more than one result per pitch. When pitches reach zero, stop play and show a result such as “Derby over — X bombs. That’s a show.” for 5 or more home runs, otherwise “Derby over — X homers. Run it back.” Preserve the clean arcade aesthetic: navy translucent glass HUD cards, white bold typography, yellow instructional accents, blue start/aim buttons, and a vivid orange-red swing button. Avoid team logos, branding, or extra game modes.