Here is the full list of all 18 Perchang achievements.
Complete a level with less than 1 second left
Complete Area Ten
Complete Area Nine
Complete Area Eight
Get 50 gold medals
Complete Area Seven
Complete a level in less than 5 seconds
Complete Area Six
Complete Area Five
Complete Area Four
Get 20 gold medals
Complete Area Three
Get a gold medal with less than 1 second left
Get 10 gold medals
Complete Area Two
Get 1 gold medal
Get 5 gold medals
Complete Area One