AI portfolio case study · Game design and build

Marble Park

A 3D marble racing game for phones and computers. You roll a glass marble through a miniature candy amusement park and race the clock, computer rivals, or friends.

My roleGame designer and art director

Built withVibe coded with Claude

StatusPlayable prototype

Play the prototype

The idea

A classic marble race in an original world

Marble-rolling arcade games are easy to learn and hard to master: steer a marble down tilted courses, dodge hazards, and beat the clock. I wanted that feel on a phone, with an original theme, original courses, and a reason to play with friends.

The theme brings together two things I love, amusement parks and roller coasters, in bright candy colors.

What it does

Eight courses through one park

Courses that unlock in order

It starts on Sugar Midway, a teaching course with gumdrop bumpers, a syrup spill, a bowl, and a cookie jump. Finishing a course unlocks the next: Bumper Boulevard, Skate Park, Splash Lagoon, Big Top, Cloud Bounce, Sunny Beach, and Boardwalk Pier.

Play with friends

Two to eight players join from their own phones or computers with a four-letter room code. Race one course, or tour the whole park with points adding up.

Practice anytime

Three computer rivals stand in for real players, so the game is always ready to play solo.

Eight marbles

Swirled glass marbles in eight colorways, from Sky Swirl to Peppermint.

Three cameras

A chase view, an angled overhead view, and a dynamic view that rises for bowls, jumps, and crowds.

Something to chase on every course

Candy coins, power-ups like Candy Comet, Magnet, Bumper Shield, and Surfboard, shortcut switches, and tricks you spin by steering in the air.

The screens

What it looks like on the phone

These screenshots come from the playable prototype at phone width. Swipe to see them all.

The Marble Park title card listing the courses, starting with Sugar Midway — Courses unlock in order, starting with Sugar Midway.

The marble picker with eight swirled glass marbles and the three camera choices — Pick a marble and a camera.

Four marbles on the starting grid of Sugar Midway, facing the first checkpoint — The starting grid on Sugar Midway, racing three computer rivals.

Design decisions

What shaped the game

The first course teachesSugar Midway introduces one idea at a time: steering, bumpers, the bowl, a jump, and a shortcut switch. Later courses build on what the player already knows.

Room codes instead of accountsFriends join with a short code. Nobody has to sign up to race.

Phone-first controlsDrag anywhere on the screen to steer. Arrow keys and WASD work on a computer, and a key switches the camera.

Each course has its own worldEvery course is a different corner of the park, from a skate park to a circus tent to a boardwalk, so unlocking the next one feels like a reward.

How it was built

Vibe coded in conversation with Claude

I directed the concept, the theme, the courses, and the way the game should feel, and tested the builds myself. Claude wrote the code, including the 3D courses, the computer rivals, and the online room codes.

Status and next steps

A playable prototype

Eight courses, practice races, and online rooms are built in, and it runs in a phone or computer browser.

More playtesting with friends to tune each course
Polish for an eventual Apple App Store and Google Play release

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Marble Park Case Study