Pantheon Ending

I just finished watching the Netflix animated show "Pantheon" and man am i having a existential crisis right now. 

If you havent watched the show please go watch! There are so many plot twists and the ending is just INSANE!

But the ending is what i wanted to talk about since im still processing what i just watched. 
The ending can be perceived in many ways, but this my take!

SPOILERS AHEAD!!

im basising my answers on this reddit post!

how did maddie create her "universe"?

maddie after dave died decided to upload. How she got to an upload centre? Im sure she knew how to get out without getting harmed by the mob of deadly robots. But it is there where she decided to go with MIST through the universe. On the way there i imagine she was non stop working. Just thinking, making plans, coding, building. She then found an uninhabited planet and used it to create her dyson sphere

What is maddie?

In most ways maddie is a "god". Since she has been alive for so many years she was able to upgrade and learn how to control pretty much everything. This is shown when she is able to bring dave and caspian back to life. Its also shown when she is able to bring her dad, caspian, and others into the dyson sphere. She is able to recreate everything that has happened in her and everyones lives just by waving her hand. She controls all the simulations, since she created all the simulations. She is their god

Were they even real people?

There were once people/ real things, in the original timeline but in the simulations they arent technically "real". But thats the question they are asking the whole show, "are these UIs or simulations real?", which in my opinion yes there are. What is real? Who is to say what is real? Its like the matrix. You live in the matrix thinking what you are seeing is real but in reality it isnt but no one can tell you it isnt until you see it for yourself. So in reality, we dont know what is real and wasnt. So everything is real to an extent. But the people in maddie's simulations are technically real. Real to their own simulations. 

Was that the real caspian or just code she made?

adding on to what i was saying⬆️ Caspian is real... Real to his simulation. 

What were the giant beings (the thing safe surf evolved into)?

This creator said it better than i ever could. The beings that were safe surf became more. They are more. 

As for why they chose nostalgia, Maddie never wanted to be a UI. She loved her bodied life, thats why she was so persistent to stay in her bodied life. She only uploaded because she had nothing to lose anymore. Her son was dead, caspian was dead, and everyone else in her life was uploaded. She wanted to go back to normal. She even said she wanted to "go back to being ignorant" "and go back to feeling pain". I also think that she has been alive for so long she just wanted to do something. She wanted to be "human" again. Be ignorant and forget everything that happened, just to live throught it again. Adding to this, it also couldve been a spur of the moment type thing. Caspian was there, and she even said that "the maddie watching this can redo" (not an exact quote), so even if they messed anything up, nothing would really suffer the consequences other than the simulation that they were in. It was an easy decision for both parties

Where are the other UIs?

The other UIs are most likely still on earth, most likely unharmed. Or not. We dont know really. 

End