GamerSafe
Other (objects, etc.) entity
Supports GamerSafe to a degree, such as having saves stored online, public achievements, micro-transactions, etc. Requires login at GamerSafe, though some games may be playable without such (with the additional features unavailable).
1
game
1platform
FLA 2011
This is available only to Flash games and does not require the games to be played at any specific website.