Aside from the achievements you'll get simply by following the storyline, there's a handful of achievements that you might miss if you don't perform certain specific actions, especially if you used a walkthrough and completed all the puzzles without much trial and error.

Thankfully, the game has an Episode/Level Selection option, allowing you to easily head directly to the Episode you need to get the achievements you miss.


Giant Cat
Episode 9 where you build the flying machine. Walk to the very end (to the right) and, after you've walked past the super long sign, you'll meet the giant cat and get the achievement.

Crybaby
In Episode 11, after crashing the flying machine, the lady washing clothes is actually carrying her baby behind her back. All you need to do is to make the baby cry. To do this, you just need to click on the bra hanging on the washing line, then click on the black shirt with the X when her back is turned and the baby is facing you.

As a bonus, you can also click on the baby to make some funny faces at him/her.

That's Gross
In episode 12, when they are all in prison, you, while playing as the chicken, have to drink out of the night pot in order to get this achievement.

Frequency Modulator
In Episode 2, tune/click on the radio more than 10 times to get this one.

Lonesome George

Note the shell of the turtle in the screeenshot. You'll need to click on it

In episode 13, where the girl is telling a fairytale based on Rapunzel, you will need to have found the turtle, brought it to the past (-50) and dumped it in the river. You will want to also plant the tree sapling so that it will dry the river in the future. Once done, travel to the future (+50), just down to the dried river, and then step on the dead turtle’s shell to get this achievement. Special thanks to Zangetsu for the tip!

To fix this, simply go back to -50, take the turtle out of the river, and then throw it in again.