All the games here are FLASH games.
Most likely it's a browser s/w problem. (old version, dirty cache, option disabled, s/w not downloaded, etc)
Flash SWF is an open multimedia format created by Macromedia (now Adobe), which also releases the free Flash player. Flash offers many great features including interactivity, animation, video, audio and small file sizes. In addition, the Flash player is available for virtually all platforms (including Windows, Mac and Linux) and all Web browsers and since the player is so widely distributed, your viewers will be able to see your distinctive. As long as you already have the Macromedia Flash plugin, any SWF multimedia project should work without having to download any additional software.
You might have never received or installed the plugin or it has become corrupted.
You can re-download it
here.