Dopamino

Inspiration

Most likely everyone over their 40s have played with dominoes as a child, and the younger the generations go, it seems the less they know about the fun of dominoes. We think it is a shame that the fun of domino gets lost, and we want to reintroduce it to all ages in a new dimension with this Mixed Reality game.

What it does

The current version of Dopamino only includes the Puzzle mode, out of the 3 base modes that we are planning to have. Puzzle mode will provide players a challenge where they will have a starting domino in green, and an ending domino in red. The goal of each challenge is to topple the ending domino by using domino pieces and gimmicks. This submission comes with 4 stages with increasing terrain challenges and more need of creativity to figure out how to topple the red domino.

How we built it

Our team of 3 developers, formerly developers of Real VR Fishing, and Vivarium, now independently, formed a start up company to develop Dopamino. The submitted version was developed in a 2-weeks period using Unity XR Interaction Toolkit, Meta XR Platform SDK, Meta XR Interaction SDK, Meta XR Core SDK.

Challenges we ran into

The biggest challenge was precisely placing small and lightweight domino pieces using only hand tracking. Dominoes are inherently unstable objects that fall easily with even the slightest touch. In the early stages, when placing a domino using the pinch gesture, unintended physical collisions occurred, causing the entire chain to topple unintentionally. To solve this, we had to design a logic that separates states—disabling physics in Build Mode so dominoes wouldn’t fall, and enabling physics only in Play Mode after placement is complete. With only about two weeks of development time, perfectly implementing weight, friction, and material feel using Unity’s physics engine was a significant challenge. Especially in an MR tabletop environment, achieving the core fun of dominoes—standing firmly without sliding, yet falling satisfyingly when hit—required extensive testing and fine-tuning.

Accomplishments that we're proud of

We successfully implemented an intuitive UI that allows players to enjoy the entire game using only their hands—no controllers needed. When the user looks at their left wrist, the Hand UI appears; opening the palm spawns a domino; and using the pinch gesture to pick up and place pieces creates a very natural flow. Additionally, flipping the palm over triggers a delete gesture, enabling an intuitive create/delete experience without requiring complex menus.

We completed a tabletop-style level design that allows everyone to play under equal conditions regardless of their real-world environment. By blending a virtual board and diorama-style terrain naturally with the user’s passthrough surroundings, the experience feels like playing with real toys. We also applied different impact sounds depending on a domino’s material, delivering a satisfying burst of “dopamine” through both visuals and audio when pieces fall.

What we learned

In a hand-tracking environment without the tactile feedback of placing real dominoes, visual cues and sound must fill in the gap. By differentiating sounds for domino-to-domino collisions and floor contacts, and adding blinking effects when dominoes are created or selected, we helped users clearly understand the results of their actions.

We learned that instead of simply placing 2D UI panels in midair, using the user’s body—such as the left wrist—as a UI anchor provides optimal accessibility without breaking immersion. Designing a natural behavioral flow—Look at wrist → Select → Pinch → Place—proved to be a core principle of MR content and a powerful form of affordance.

What's next for Dopamino

Puzzle mode is the “learning and practice” mode of the game to help players get used to dominoes. The next content will be a sandbox/creation mode where people will be able to create their own challenges utilizing the space of their rooms and the wide variety of dominoes and gimmicks introduced in the future. We will then proceed to add Multiplayer mode where players can share their created domino toppling designs and topple together with friends.