Plot? Acting? Confusion?

Rating: 2/10 (28 June 2019)

First off, it was very hard for me to leave a 3 star review for this movie, considering I believe it deserves less.
There were way too many plot holes in this film and way too many goofs. Read the list of goofs, if interested.
The only reason I rated this a 3 star was because of the concept. The concept has great potential, but it definitely wasn't followed through with this film. I love the whole "evil twin/clone", doppelganger side of this story, but I felt quite filled with disappointment after the first 30 minutes or so.
Once the "Tethered" began speaking, that's ultimately where everything went downhill. It was a mixture of someone needing a glass of water (like Spongebob) and forceful demonic sounds, screeches, and voices. I found it more comical than anything.
The acting was terrible, to say the least. The only one's I felt were even worthy of having listed as good acting would have to be Kitty and Zora. No disrespect to the other's involved in this film though, there is potential elsewhere, I'm sure.
I do have a lot of questions for this movie, but obviously there won't be any answers for them. I can draw my own conclusions, even if those conclusions don't make much sense with the plot. Quite frankly, nothing made sense with the plot.
So, why weren't any of the other "Tethered" indiviuals mimicking their people? The only one that was mimicking at all was Jason (the son). Later in the movie, it showed where all the "Tethered" came from, how they take on the movements of their counterparts, but right off the bat, that wasn't included.
HUGE SPOILER ALERT IF YOU CONTINUE READING FURTHER!
At the end we reveal that Adelaide (The mother) was actually snatched up by her doppelganger in the mirror room and they switched roles in each other's lives.
Why did Adelaide decide to rally up everyone else's doppelganger to kill their doubles? How did that tie into her story at all? If she wanted revenge or to find her evil counterpart, she could have went on that mission alone. I don't understand how the other's come into play and how it has any relevancy in the plot or the first 30 minutes of the movie.
END OF SPOILER ALERT!
In conclusion, the movie had great music (yet it never matched the movie at all), good acting (only two characters), and a great concept (with a terrible carryout).