Portal

Portal is composed of brilliant explorative puzzles. With a gun-like machine called the Aperture Science Handheld Portal Device, the player can create blue and orange portals which connect two flat locations. If you go through the blue portal, you will come out of the orange portal (and vice versa). If you shoot the floor and then shoot a distant wall, you can then jump into the portal on the floor and come out of the portal on the distant wall.

What's more, momentum and velocity are maintained through portals, which makes them fantastic for teaching physics. If you fall a long distance through a portal, you can use that momentum to "fling" yourself horizontally across a great distance (see below).

Because of Portal's brilliant use of FPS to create inherently nonviolent gameplay, it has been hailed as one of the most innovative video games ever.

Portal takes place in the universe of the game Half-Life. Beware spoilers below.

Portal begins when you wake from stasis and find yourself inside the Enrichment Center for Aperture Laboratories, a massive research facility. The voice of a maternal AI named GLaDOS (Genetic Lifeform and Disk Operating System) tells you to prepare for several tests. If you successfully get through every test, GLaDOS promises that you will be rewarded with cake and grief counseling. The goal of each "test" is to reach the exit on the other side of the room with the assistance of a gun-like machine called the Aperture Science Handheld Portal Device and a large block called the Companion Cube. The obstacles in each level become increasingly dangerous.

Over time, GLaDOS's motivations are slowly revealed to be sinister. She continues to insist that the rooms are simply experiments, despite the fact that the obstacles include gunfire and toxic liquid that can kill you. Eventually, you discover a dilapidated section of the lab, ignoring GLaDOS's pleas to return to the test course. Graffiti on the walls indicates that several test subjects have died there. It's implied (and later confirmed) that GLaDOS murdered everyone in the science labs with a deadly neurotoxin.

You must then attempt to destroy GLaDOS by attacking her system mainframe. A massive portal malfunction disables GLaDOS and leaves you unconscious on the surface, where (in the rereleased version) you are dragged away by a robot. The game ends with a shot of the cake promised by GLaDOS, deep within the Aperture complex.

Representation: The playable protagonist, Chell, is a woman of color. GLaDOS, the AI antagonist, is also female.

You can save at almost any point of Portal simply by pausing and selecting Save. If you die, you are automatically returned to the last significant accomplishment in your gameplay (pressing a button, passing through a door, etc.). The game's many levels provide nice breaking points.

The difficulty of the puzzles increases as the game progresses, and some of the later puzzles can be pretty tricky depending on your ability to recognize solutions and grasp the game's mechanic. Younger kids might need the assistance of a parent, and everyone else may want to phone a friend!

Because Portal is an exploratory puzzle game (often with multiple solutions), it's a great idea to try playing a few levels with your kids and seeing what methods they choose to solve each room. Try solving a few together, and talking about the process they go through to solve each puzzle.

Here are a few questions you could ask to start a conversation:

• Do you believe that artificial intelligences have the capacity for emotion? Does GLaDOS have a personality?
• If a person volunteers to be experimented upon, does that count as consent? At what point does the experimenter go too far?
• Were you surprised when you realized you were playing as a woman? Why?
• Can you separate the humor from the drama? What about GLaDOS is funny, and what is scary?
• What are some other games that don't rely on violence?