Bejeweled

The casual game i played was Bejeweled:

http://free-online-games.nu/bejeweled.html

The only valid move is to swap adjacent gems to make three or more gems of the same color line up horizontally or vertically. When that happens, you earn points, the lined-up gems disappear, the gems above them fall and the extra space is filled with random gems. Once this has happened, there may once again be three or more gems lined up, in which case the process is repeated. This is called a "cascade". The game ends when there are no valid moves.

The game is quite enjoyable for the first 10 or 15 minutes, until the moves become harder to find.. then it starts to get boring and more and more tempting to just quit.

There is quite a lot of concentration required as you need to find a move that will make three or more gems of the same colour line up horizantally or vertically. When you get further into the game, the moves you can make become fewer and fewer so a lot of concentration is needed, this also adds to the immersive aspect of the game as well.

I think this game is aimed at anyone and everyone, there is no specific target, hence the term 'casual game'

The immersive aspcet of the game is not emotional, just a side effect of the concentration required in playing the game

The game is easy to learn, but hard to master.. you need to know what moves to make and always be one step ahead, because one move could prevent you from making another move, and then effectively end your game.

Their is no narrative in the game, just instructions to begin.. after that you're on your own

There is no social interaction to the game either, its a one player puzzle game.. usually people like to play these games by themselves anyway.