Report updated Mar 31, 2026
Fill - one-line puzzle game
v8.6.0Casual gamers and individuals looking for quick, accessible brain-training exercises during daily downtime or commutes.
What Is Fill - one-line puzzle game?
Launched Apr 27, 2016
Updated Oct 2025
What users think iIndependent intel reports to help builders create better apps or enhance existing ones. Still in beta, accuracy and relevancy get better every day. For informational purposes only.
What does it look like?
What are the key features?
Connect-the-block style puzzles requiring the user to fill all blocks using a single continuous line.
Includes 2,000 unique puzzles across 4 levels of difficulty.
Provides assistance for difficult puzzles at no additional cost to the user.
Positioned as a mental exercise tool to improve work efficiency and prevent cognitive aging.
What do users think? iIndependent intel reports to help builders create better apps or enhance existing ones. Still in beta, accuracy and relevancy get better every day. For informational purposes only.
“Recent user voice shows a frustrated sentiment. Users appreciate engaging gameplay and offline playability, but report excessive advertising and broken ad-removal purchase.”
What Users Love
One of my absolute favorite puzzle games.
It really keeps my mind busy. One of the best game to relax.
Not endless, not too hard, not timed, no online required
Playing it as an offline game solves the issue.
Pain Points
You spend more time waiting to clear the ads than it takes to do a puzzle.
There are way to many adds and it gets on my nerves.
I paid for the ad remove... but now the game is unplayable due to the ads
I pay NTD100 to remove ads but IT DID NOTHING pls fix this problem
I already communicated three times but no answers.
Requested assistance or a refund and have not gotten any response as of yet.
High confidence · 99 reviews available
What are the pros and cons?
Pros
- Large, established user base with over 100,000 ratings.
- High-volume content library (2,000 puzzles) provides long-term engagement.
- Simple, intuitive core loop that is easy to learn and hard to master.
Cons
- Aggressive ad-monetization strategy is causing high churn.
- Critical failure in IAP functionality (ad removal) damaging brand trust.
- Non-existent customer support loop, leading to unresolved user complaints.
What is the market outlook?
Growth Opportunities
- Competitors can capture the 'frustrated user' segment by offering a cleaner, ad-light, or subscription-based alternative.
- Opportunity to introduce a 'Premium' version that is truly ad-free to rebuild trust.
- Potential to expand into social features or daily challenges to increase retention.
Market Threats
- Negative sentiment trends may lead to store visibility penalties or lower conversion rates.
- Competitors with better UI/UX and non-intrusive monetization could easily displace this app.
- Potential for platform-level intervention if billing issues persist.
What are the key takeaways?
Fill - one-line puzzle game is a frustrating puzzle app that is completely free. With a 4.1/5 rating from 100.3K reviews, it frustrates many users from users. Users particularly appreciate engaging gameplay, though excessive advertising remains a common concern.
Best for: Casual gamers and individuals looking for quick, accessible brain-training exercises during daily downtime or commutes.
How much does it cost?
Model: free
The app follows a fully free-to-play model, likely monetizing through in-app advertisements rather than gated content or subscriptions, emphasizing accessibility to drive high install volume.
iOS Version
8.6.0
Android Version
8.6.0
Release Date
Apr 27, 2016
iOS Price
Free
Android Price
Free
Developer
GAMINCAT, INC.