Because this site is currently based on Flash Games, All of the games in the following categories are no longer playable:
NES, SNES, Sega, GBA, and GB.

Atari Games are currently the only games that are playable.

If I can figure it out, then all the other games will again be playable.
(Unless you have an older version of the browser you use, that still has Flash capability, that is the only way you will be able to play all the FLASH based games)