Mozilla created a retro style game that is based on HTML 5. It only takes 1 hour to complete all 20 achievements. I find it's fun to play. The point is to encourage HTML 5 application.
my screenshot: (arrow: my toon)
Here is how to complete the last two hidden achievements. (following is quoted)
# 19, For Science
There is a place down the town to the right where you can see portals. Just get into the portal and wait for the cake to come out and grab it. See the images on how to do it on your own.
# 20, Rickroll’d
The other hidden achievement is located just above town in the forest where are are ogres guarding the cave. Its a bit tricky and confusing so remembering which door you entered is important. You could test each door until you find the place where there is Rick singing. Just click on him and get the achievement.
