Surprisingly, the Snake game Easter Egg that was revealed on YouTube this week isn’t the first example of a playable game on the online video service. On the contrary, for the last two years YouTube’s video annotation feature has let users add a measure of interactivity to their videos, in the form of clickable buttons that lead down different paths.
While a lot of the “interactive videos” to be uploaded in that time come across as lazy, cheesy or generally unwatchable, there are a few that actually take the idea in some interesting directions.

(full article)