you found..
an archive of like a billion working flash games (and more)
ok its not a billion its more around 100000, but still
bluemaxima's flashpoint is a webgame preservation project, making thousands of old flash games and animations and web games in general playable offiline through a neat launcher
heres something to start with, play the gateway games
bonus: bluemaxima's kahvibreak. same concept just old java 2 micro edition phone games instead