Get Your Ghost

Inspiration

We wanted to bring the classic thrill of "Arcade Survival" into the real world. The idea was simple: what if the space around you wasn't safe? We wanted to create an adrenaline-pumping experience where players have to be physically active, turning around and scanning their environment to defend themselves against supernatural entities.

What it does

Get Your Ghost is an endless AR survival game. 360° Gameplay: Ghosts spawn randomly around the player (behind, left, right, or front). Survival Mechanic: The ghosts relentlessly approach the player. If they get too close (enter your personal space), you lose a heart. Combat: Players must physically tap the ghosts on their screen to banish them and score points. Dynamic Difficulty: Some ghosts move normally, while others "rush" when they get close, testing the player's reaction time.

How we built it

we built this project using Lens Studio.

Scripting (JavaScript): We wrote custom logic for the GameManager to handle the game loop (Start, Score, Game Over) and a GhostController using Vector math to calculate distance and direction relative to the camera. State Machine: We implemented a simple AI behavior where the ghost calculates the distance to the player and switches between "Patrol" and "Rush" speeds. Interaction: We used Raycasting and Interaction Components to detect taps on 3D objects in world space. Optimization: We utilized low-poly 3D models to ensure smooth performance across various devices, including mid-range Android phones.

Challenges we ran into

The biggest challenge was Cross-Device Compatibility, specifically regarding AR Scale and Interaction.

We noticed that on different devices (e.g., iPhone vs. Android), the AR world scale was interpreted differently, making the ghosts appear too small or "unkillable" because the touch hitboxes were too small. The Fix: We implemented a "Forgiving Hitbox" system using invisible colliders that are larger than the visual 3D model, ensuring that players can reliably tap the ghosts even on smaller screens.

Accomplishments that we're proud of

Creating a Full Game Loop: Unlike many AR filters that are just visual effects, we successfully built a complete game with a Start Menu, Scoring System, Health Management, and a Game Over state with High Score persistence.

Solving Cross-Device Interaction: We are particularly proud of solving the "Scale & Input" issue on different devices. Getting the tap interaction to work smoothly on both high-end iPhones and mid-range Android devices (like the Realme series) required implementing a custom "Invisible Hitbox" system, which significantly improved the UX.

The "Juice": We managed to add polish that makes the game feel responsive specifically the particle explosion effects when a ghost is banished and the dynamic speed changes ("Rush Mode") when ghosts get too close.

What we learned

AR UX is Physical: We learned that designing for AR isn't just about what's on the screen, but how the player moves. Forcing players to physically turn 360 degrees creates a level of immersion that traditional mobile games can't match.

The Importance of invisible Colliders: We learned a hard technical lesson about Raycasting. Relying solely on visual meshes for input is unreliable in AR; using separate, larger physics colliders is essential for a frustration-free experience on smaller screens.

Optimization is Key: We learned how to balance visual quality with performance by optimizing textures and compressing audio

What's next for Get Your Ghost

Spatial Audio Radar: We plan to implement 3D Spatial Audio so players can hear exactly which direction a ghost is approaching from (left, right, or behind) without having to spin around constantly.

"Don't Blink" Mechanic: We want to add a new ghost type that only moves when the player isn't looking at them, utilizing the camera's field-of-view data to create a terrifying "Weeping Angel" style mechanic.

Hand Tracking: Replacing the "Tap to Kill" mechanic with Hand Tracking, allowing players to blast ghosts using palm gestures for a more immersive "supernatural hunter" feel.

Global Leaderboards: Integrating Snapchat's Cloud Storage to enable a global leaderboard, allowing players to compete for the highest survival score worldwide.

Built With

• blender
• javascript
• lens-studio
• photoshop
• snapchat