Story related, not missable
Last achievement to get in Chapter 1
Flower Garden:
Puzzle in the mushroom window, use triangles:
1)Just rotate the pieces so the pairs of colored tubes match up correctly.
2)Next you can turn the faucets on the flower stem on: Make sure you start from the violet faucet and use all of them ending up with the red one, as there is an achievement for using all faucets!!
Once you use the red one, the balloon will take off
Achievement unlocked