Purr trail

Ever played a game with your eyes closed? Feel the vibrations, locate the hidden target, and find it using touch instead of sight.

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Inspiration

Since the RevenueCat theme naturally made me think about cats, I wanted to keep that idea in my game. If you've ever had a cat, you know they purr. At night, when you can't see them, you can hear that familiar purr and know they're close or not. But a purr isn't only something you hear - you can feel it as a vibration.

That made me wonder:

What if vibration wasn't just feedback in a game, but the actual way you played it?

That simple thought became Purr Trail.

What it does

Purr Trail is a haptic-first hidden-object game. A lost kitten is hiding somewhere in the darkness. You can't rely on your eyes to find it. Instead, you explore the screen by moving your finger across it and feeling the intensity of the vibrations.

The closer you get to the kitten, the stronger its purr becomes. The goal is simple: Follow the purr. Find the kitten.

As the levels progress, the challenge increases. The search area becomes larger, giving you less time to locate the kitten and forcing you to rely more on intuition, memory, and your sense of touch.

How I built it

I built Purr Trail as a solo developer, from the game concept and mechanics to the UI, gameplay, and monetization.

The core loop is: Touch → Explore → Feel → Locate → Find

I designed the game around Android haptics, making vibration the core gameplay mechanic, not just an extra effect. The dark UI reinforces the idea that players must rely on touch rather than sight.

Tech & Tools

  • Code: Kotlin + Jetpack Compose
  • Design: My own ideas + AI-assisted image generation with ChatGPT
  • Monetization: Google AdMob + RevenueCat Ads
    • Banner: Home screen
    • Rewarded Ads: Earn extra lives
    • Interstitial Ads: Between-game breaks
  • Sounds: Pixabay
  • Jury testing: Redeemable codes for bonus game access and extra lives

Challenges I ran into

1. Making vibration intuitive

The biggest challenge was teaching players what the vibration means and finding the right balance for the kitten's continuous purring. It had to feel natural without becoming annoying.

2. RevenueCat & AdMob in production

The RevenueCat integration worked well in the sandbox environment, where I was able to test the full ad cycle and verify the expected behavior. In production, however, ad delivery and tracking behaved differently, and I encountered some issues with ads not appearing as expected in the RevenueCat dashboard. This highlighted some differences between the sandbox and production environments and required additional troubleshooting during the launch process.

3. Finding the right monetization balance

I don't personally like paying subscriptions just to play games, so I wanted ads to keep the game accessible. I tried to make them as unobtrusive as possible: interstitials after every two games and only after level 3, while rewarded ads let players earn extra lives.

Accomplishments I'm proud of

I'm proud that I turned a simple idea - "a cat's purr is a vibration" - into a new way to play a game. The interesting part is that vibration isn't just feedback after something happens. It becomes information that helps you win. Instead of vibrating when you win, your phone vibrates because you're getting closer to winning.

Feel → Interpret → Locate → Win

I think that small shift creates a genuinely different game mechanic.

What I learned

The biggest thing I learned is that interesting ideas can come from iteration - and you should never give up on finding one.

Before Purr Trail, I built two small apps. The first was too simple to keep players interested. The second explored using the phone's torch, but I struggled to turn the light into an engaging game mechanic. I then started experimenting with haptics, thinking about what vibration could do beyond the usual feedback.

That's when Purr Trail clicked.

I learned that it's okay to leave an idea, come back to it, and try again. Keep experimenting, keep thinking, and never give up - the right idea might be one attempt away.

What's next for Purr Trail

Purr Trail started as an experiment, but I'd love to push the idea further. A natural progression could be:

  • Adding more game levels
  • Moving kittens
  • Different purring patterns
  • Environmental obstacles
  • More complex haptic puzzles

I'd also like to experiment with other phone capabilities, such as the gyroscope and motion sensors, to make the physical phone itself part of the game.

Ultimately, I want Purr Trail to become more than just a hidden-object game. I want it to be an experience where:

You can't always trust what you see. You have to trust what you feel.

Follow the purr. 🐾

Built With

  • admob
  • jetpackcompose
  • kotlin
  • revenuecat
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