Angry Birds is one of the most successful mobile games created so far.

What exactly makes Angry Birds so popular and so addictive?

Psychologists, user interface experts, and game designers

have identified a few reasons.

We'll explore them in this virtual environment

which is modeled after the same principles as the Angry Birds world.

First, Angry Birds is enticingly simple.

It doesn't take much time or effort to get the hang of it.

And develop what psychologists call a "schema".

A mental model of the game and all of it's rules.

Ow.

You use your finger to pull a slingshot and fling one animal — in this case me,

at another less likeable animal's fortresses until they crumble.

And that's pretty much it.

In Angry Birds you later learn

that the pigs were stealing the birds' eggs.

Second, the game obeys the laws of physics,

most of the time.

Our brains evolve to recognize cause and effect.

As children we learn to expect

that our actions have predictable consequences.

If you pull lightly on the slingshot,

the projectile won't go very far.

Greater force equals greater distance,

but the angle at which you pull matters too.

The slingshot in Angry Birds works in exactly the same way.

The game even traces the arcs of birds flying through the air,

helping you improve your slingshot skills.

Similarly, the different structural materials in the game

— wood, glass, stone — splinter, shatter and crumble in realistic ways.

Angry Birds also keeps us hooked with instant gratification

and easy access to new challenges.

Buildings topple within seconds of releasing the slingshot,

and as soon as we finish one level there's another one

available to us without delay.

And when you finish the entire game,

there will probably soon be a new version for you to download.

For Scientific American's Instant Egghead, I'm Ferris Jabr.