Karma Kat

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Inspiration

We realized that browsing Reddit is often about discovery—finding a hidden gem of a subreddit or a funny post. We thought: "What if a cat did the doom-scrolling for you?" We wanted to create a non-intrusive, delightful daily ritual that celebrates the diversity of Reddit communities, from r/gaming to r/nosleep, wrapped in a comforting, high-fidelity visual package.

What it does

Karma Kat is a daily idle game where you care for a pixel-perfect adventurous cat.

Strategy: You pack a backpack with specific combinations of Food and Tools (e.g., A Flashlight + Sashimi increases the chance of finding horror-themed loot).

Exploration: The cat travels to real subreddits (simulated) based on your loadout.

Reveal Mechanic: When the cat returns, players receive a "dirty" polaroid. They must physically "scratch" (rub) the screen to reveal the photo and the souvenir, adding a tactile sense of discovery.

Room Evolution: The isometric room dynamically changes based on your history. Visit r/plants often? Your room fills with greenery. Visit r/gaming? A console appears. Your room becomes a visual representation of your Reddit browsing habits.

How we built it

We built Karma Kat using Reddit's Devvit platform and React.

Visual Engine: The core achievement is the Zero-Asset Isometric Engine. We didn't use heavy 3D libraries or external images. Every wall, bed, and furniture piece is drawn using pure CSS with advanced transforms (rotateX, rotateZ, gradients). This ensures the app loads instantly and feels native.

State Management: We used React Hooks to manage the complex state machine of the cat's journey (Home -> Prep -> Away -> Reveal).

Interaction: The "Scratch Card" effect uses a customized HTML5 Canvas layer with global composite operations to simulate the erasing effect.

Challenges we ran into

Balancing "Idle" vs. "Boring": Idle games can easily feel unengaging. We solved this by adding the "Scratch" mechanic and the "Backpack Strategy" layer, so players feel they have agency over the random outcomes.

Devvit Constraints: Adapting a game loop to the constraints of a Devvit post (webview) required careful handling of state persistence to ensure the cat remembers its journey even if the user scrolls away.

Accomplishments that we're proud of

The Aesthetic: We are incredibly proud of the "Cozy" vibe. The day/night cycle that changes the room's lighting in real-time creates a genuine sense of atmosphere.

The Scratch Interaction: It feels surprisingly satisfying to "clean" the polaroid. It turns a simple text notification into a playful mini-game.

Dynamic Decor: Seeing the room evolve based on gameplay makes the experience feel personal and grounded.

What we learned

We learned that "micro-interactions" (like the meow bubble when poking an empty bed) are just as important as the main loop for player retention. We gained a deeper appreciation for the Reddit API and how subreddits can be categorized into "biomes" (Scary, Funny, Wholesome) for gameplay purposes.

What's next for Karma Kat

Social Visiting: We want to allow cats to visit other players' rooms and leave gifts.

Community Events: Special "Expeditions" where the whole community works together to unlock a new subreddit biome (e.g., "The Great r/Place Expedition").

Wearable Accessories: Fully implementing the "Costume" system where the cat wears gear from the subreddits it visits (e.g., a diamond hands tie from r/wallstreetbets).

Built With

• api
• css
• devvit
• hono
• html5
• javascript
• react
• reddit
• tailwind
• typescript
• vite