PROTIP: If you don't like to keep a key down for so long, you can press the key and WHILE pressing it, click outside the game (address bar, task bar, anywhere else on the page itself works too). You can now release the key and, since the game lost focus, it won't realize the key was released. When you're done, click on the game again and tap the key. The action will stop.
For those of you trying to find the secret medal, I guess it ain't much of a spoiler to say this: Play the game like you normally would to beat it, but go beyond the place where the game's making you believe it ends. It'll take some wits to reach the place, but it can be achieved in one or two in-game years.
As for the game itself, it left me speechless. Very interesting concept and neat execution. I trusted this would be great because Deep Sleep was pretty awesome, but this totally surpassed my expectations and, more importantly, was great in very much different ways than Deep Sleep was.
I also invented the Evil God ending, where you make all the effort and travel to the top of the volcano, only to stop there at the tip and let time pass and all humanity die. And possibly laugh all the way.