No, all screenshots are taken in the game. The green and red glowing boxes are indicators above the doors showing whether the door is locked or not. If there is no indicator, then the door is a decoration.
Yes, the game is really dark in places, so I added a flashlight. Since there is no tutorial in the game, the next moment probably needs an explanation: the door at the back (which gives a message to return here later) is the end of the game, now it is closed and you need to kill 3 bosses to open it. Now you need to go through the open door and you will find yourself in a large room with 2 closed doors. You need to climb to the elevation in the room, there will be a terminal. When you approach him, those doors will open.
Also: press Tab while next to the terminal and you will save the game. While in the inventory next to the terminal, you can modify weapons, create new ones, and create upgrades.
If you have questions, don't hesitate to ask them.
P. S. In the screenshot below, you can clearly see the terminal on the right.
