You’d been woken up by an entity which created you. It put you in a testing area and wants you to complete the puzzles and open the end gate. When you open the gate, the test is finished and you complete the task which the entity gave you.
The area you woke up in has many elements such as; puzzles, collectibles, crafting. You are free to roam and see every part of the map. Then you need to put to-do’s in order to open the gate. Some parts of the map need certain requirements for you to enter. You can also collect map pieces and combine them see every collectible in the map.