There are thousands of games on the market for Madden game, but buy it on the Xbox and he's out of luck if he's got a PS2.
Here is a basic breakdown of what classifications of games there are, plus a brief explanation of what they are like as well as a few of the most popular games of the genre.
* '''Compatibility'''. Remember that each gaming system has proprietary games, so if you know that you are buying for a Nintendo owner, make sure the game is for the particular type of Nintendo the gamer owns. Same even within a series of game consoles from the same manufacturer, PalyStation 3 and Playstation 2 games may not be cross compatible. Likewise, if the game is for PC, check to make sure that you choose the right operating system, either Windows or Mac.
* '''Age Appropriateness'''. Be sure to check the ratings for choosing an age-appropriate game. Many of the shooter games are likely not appropriate for younger players and should be avoided. Go to ESRB for more information.