Cernan Mari’s review published on Letterboxd:
"Dual" made little effort to establish the rules of the world in which they lived, which added a sense of reality to the film, but I believe it could have used a little context to get us on board with everything. Yes, this world is strange from the start, but it never feels completely separate from our own and is actually under-explored. Also, the complete lack of depth and jokes that mostly fall flat, don't seem to fit, and are too extreme and feel that way - and, worst of all, are guilty of not being well thought out. Very little of this film feels cohesive, and it appears to be more of the director's desire to convey what they believe is clever but fails to convince. How can the authorities not know who the original is and who the clone is if the clone only knows what is communicated? You can't have incredible technology if you can't assume the most fundamental elements. Nothing is adequately explained, particularly how or why this dysfunctional bleak society operates.
Personally, I think the real reason to watch "Dual" is for the dueling Gillan performances. She gets to play two different versions of the same character, and she really shines in the subtle differences she exploits. I liked the clone's passive aggression in re-examining her original's flaws, and I liked how quickly she interrogated her original while making casual, catty judgments. There's something unique about this world among the well-troped subgenre of doppelgangers and jealous clones; it's a shame more isn't done with the concept.
Overall, "Dual" is not a great film; it is "okay," but it is a frustrating experience. The director has a clear artistic vision here; it just didn't fully gel for me because I felt the tone and plot choices limited what could have been a far more emotionally engaging and intellectually fascinating story. Furthermore, the numbing finale is infuriating and far too cynical for its own good, rendering the journey pointless.