There is no shortage of free games. The problem is that most of them spend your attention before giving you anything, and by the time you find out whether the game is any good you have already decided to close the tab.
The three things that actually predict fun
Time to first input
How long from clicking the link to doing something that matters. Under ten seconds is good. A loading bar, a splash screen and a menu will each cost you more than the game will earn back.
An obvious goal
You should understand what you are trying to do by watching for five seconds. Get further. Get bigger. Do not touch the red thing. A game that needs a tutorial to explain its goal is a game you will not finish learning.
A cheap restart
Failing should cost seconds, not minutes. The games people play for an hour are almost always the ones where a run lasts thirty seconds, because losing is not a punishment, it is the loop.
What our own numbers say
We record how long each game stays open. Across the catalogue the median session is about six seconds, because sampling quickly is how people use a shuffle button. What separates the games people stay on is not a higher median — it is a long tail. A game that holds anyone holds them for minutes.
Games that pass the test
Flip Bros
Instant start, one input, immediate feedback. The most played game in the catalogue and the clearest example of the pattern.
Tunnel Rush
Pure reaction. A run is over in seconds and the restart is instant, so five minutes is dozens of attempts.
Crazy Cars
Short loop, quick restart, visible score. Nothing to read before you start.
Swingo
One button and a number that goes up. Difficult to explain why it works and easy to keep doing.
Cubes2048.io
You understand it from the first five seconds because you already know both halves of the idea.
Draw Climber
A control scheme you have not used before, which buys curiosity without needing a tutorial.
Tetris
The benchmark. No explanation needed for most people and no natural point at which to stop.
Perfect Slice
One satisfying action, no time pressure, and it looks good doing it.
What to avoid
- An unskippable video before the game. In a ten-minute session that is a tenth of your time on an advert, and a game that opens with one will interrupt you again later.
- A name entry screen. It is the clearest possible signal that the game wants something from you before it gives you anything.
- Long loading bars. Usually an engine and an asset bundle, neither of which makes the game better.
- Energy or lives systems. Those exist to make waiting uncomfortable enough that you pay.
Fun is mostly the absence of friction. Everything above is a way of measuring friction.