Here is the full list of all 15 Double Pug Switch achievements.
Collect 500 gold
Dimension switch 200 times
Bark at Lord Sker
Beat Professor's Laboratory
Beat Prehistoric Dogs
Beat Steam Powered Pups
Beat the MeowTopia
Purchase 5 hats
Collect 1000 gold
Get a Purrfect run in a standard level
Collect all purple coins in one level
Beat First encounter with Sker
Turn Sker back to good
Complete a level wearing a hat
Fail on tutorial screen