Fill - one-line puzzle game

Contains adsIn-app purchases
3.8
61.1K reviews
5M+
Downloads
Content rating
Teen
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image

About this game

Sharpen your mind with a connect-the-block-style one-line brain training puzzle game.
A simple but addictive one-line puzzle game that’s completely free to play.

Your brain becomes more active the more you play.
During your commute, before you sleep… enjoy downtime with brain training.

The rules are extremely simple.
Just fill in all of the blocks using only one line.

Use hints for puzzles that are too hard to solve.
Hints are also free, of course.

4 levels of difficulty.
A whopping 2,000 puzzles.
Don’t get too cozy—the puzzles get harder as you go along.

One-line puzzles are mathematical problems with origins in the early 18th century. First posed in Königsberg, the original puzzle revolved around the town’s Pregel River.
Mathematical thinking is said to increase work efficiency and prevent aging.
Whether math is your bane or your forte, be sure to give this game a try.
You’re sure to get hooked on these puzzles!
Updated on
Jul 13, 2022

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
No data shared with third parties
Learn more about how developers declare sharing
No data collected
Learn more about how developers declare collection
Data is encrypted in transit
Data can’t be deleted
3.8
61.1K reviews
StorybookStone
April 21, 2022
After the first 5 levels, you get 20 seconds of ads after every level. There seems to be about a 20 sec window of cool down between ads so if you complete two levels within 20 seconds, you're basically guaranteed to hit another ad. If it takes longer than 20 seconds to beat a level, you will get an ad no matter what, and it's about 7 seconds of ads, then followed by 5-10 seconds to close out of it. This game forces you to watch ads as much as you're allowed to play.
7 people found this review helpful
Did you find this helpful?
A Google user
December 10, 2018
Thw controls worked fine. The graphics were simple and worked fine with the game. It was just too easy, and after seeing the repetitiveness of the puzzles you can't see much else while playing. Same puzzle diffrent starting point was a huge part of it. My excitement for the game was high with the sheer quantity of levels, but dwindled after noticing this wasn't a labyrinth of puzzles, but a hole that just got more and more boring the deeper you go. Its fin for about 30 minutes. Get it on a lunch break and forget about it.
185 people found this review helpful
Did you find this helpful?
A Google user
January 5, 2019
I went through 200 levels and they all felt very similar. It has a painfully slow difficulty ramp. This by itself does not make it a bad game, however all of the puzzles seems to require the same two or three tricks to solve them. it does not challenge you to come up with new ideas, it simply teaches you to mindlessly fill out shapes. Perhaps the difficulty issue could be solved by allowing players to move to harder levels quickly, but it forces you to play through hundreds of trivial levels.
16 people found this review helpful
Did you find this helpful?

What's new

Improved advertising experience