Load Scene and keep Enemy and Puzzles dead/done

Hi everyone. I'm developing a game 2D, and I use many scenes to do 1 level. In each scene, there are puzzles and enemys. If I die, I just reload this scene, and move my character to the begin of the scene. But if I pass by a scene, and I go back there, when I load it, it must be like when I left. In other words, the puzzle must be done, and the enemys that I killed, must be dead. **So my question is... How can I do it?** Studying and searching for exemples like this, I think the only why to do it, is saving all the objects informations on a script, and using it when loading again this level. So it will see if there are some enemy alive, the position of each object from puzzle, and this stuffs, but I don't know if it's the best way to follow... If someone understand what I'm trying to say, and could help me, I'd be very grateful!! Thank you *Sorry my bad english*