Overview
All the presents and secrets with maps, screenshots, and text. No need to watch any videos.
Foreword
Enormous credit is due to lilxoriss (see their guide here) and Ahrk Sierot (who made the YouTube video below).
I decided to make this guide as an option for people who wanted maps with the locations of the presents and for people who prefer text-and-pictures over videos, and also to fill in a little bit more information for other collectibles. This guide would not exist without the above-mentioned wobblers, so thanks!
Train
The second-to-last carriage of the train that travels around the city contains a present.
East Island
Central Island
Enter the car to permanently unlock it.
Head up the elevator and walk to the farthest room.
Take the elevator and to the cubicle behind the elevator upstairs.
West Island
North Island
Jungle Island
This building is relatively on its own atop a hill.
The bush is near a path that leads up to the temple
The present is in the basket of the balloon but remains on the ground if the balloon moves.
Temple
The left door contains a chest with presents and a part of the Explorer outfit.
The right door contains the hidden path solution, which I have put below.
Contains presents and a part of the Mummy outfit.
Contains presents and a part of the Explorer outfit.
Take the left-most door for the path forward.
The left-side door will take you to a dead-end with a chest containing presents and a part of the Mummy outfit.
Going back out, take the right-side door to continue with the temple and find a chest containing presents and a part of the Explorer outfit.
Go all the way around the U-shaped room to find a chest containing presents and the final part of the Mummy outfit.
The final puzzle is a Simon Says puzzle; simply repeat the pattern as it reveals each new step. Be careful not to start before it’s finished showing you each step. If you make a mistake, you have to start over entirely, so be patient to avoid making silly mistakes. Completing the puzzle will build a bridge that provides a lot of presents and the final part of the Explorer outfit.