http://en.wikipedia.org/wiki/Game
Key components of games are goals, rules, challenge, and interactivity. Games generally involve mental or physical stimulation, and often both. Many games help develop practical skills, serve as a form of exercise, or otherwise perform an educational, simulational or psychological role.
A GAME is not a TOY. Those are two different things, but since both are usually connected to childlike play, people seem to confuse them.
A game console isn´t a toy because it´s a mere game-player. Without a game inserted, it simply is a electronic device meant to play something on it, like a CD player. If you insert, say, Tetris DS into the DS, then you can play a game with it. If you insert Electroplankton, THEN you are playing with a toy.
The device itself isn´t a toy, it´s a program player. It´s contents is interchangeable, with no distinctive character of its own.
# If no goals are associated with a plaything, it is a toy. (Crawford notes that by his definition, (a) a toy can become a game element if the player makes up rules, and (b) The Sims and SimCity are toys, not games.) If it has goals, a plaything is a challenge.
# If a challenge has no “active agent against whom you compete,” it is a puzzle; if there is one, it is a conflict. (Crawford admits that this is a subjective test. Some games with noticeably algorithmic artificial intelligence can be played as puzzles; these include the patterns used to evade ghosts in Pac-Man.)