This is the first level with Garibaldi, the dog that occupies a 2×2 square. This is a good opportunity to get the “Summersault!” achievement – Simply right-click on Garibaldi 16 times to spin him 4 times.
At this point you should have all the achievements for completing the chapters as well as the achievements for unlocking dogs.
A couple of achievements you may have missed:
Simply click any dog on any level 10 times in a row to get this achievement.
If you missed my note on Level 10, this achievement is simply for spinning Garibaldi 4 times (Right-clicking 16 times). They can be found on Level 10 and many other levels after that – look for the dog that takes up a 2×2 square.
I unlocked these pretty early through natural play, but this might not happen for you if following this guide due to rotating less. If you don’t have this by the time you complete all levels, then simply load up a level and click dogs for Pup-arazzi or right-click dogs for Dog Tornado, until you get the achievements.
As the description states, mute and unmute the sound in the options menu 10 times.
Simply spend 2 hours in-game. This may happen during normal playtime or if not, you will have to simply leave the game open until it does unlock.