As another reviewer stated, it's not bad to watch once. It has some elements that make it engaging, like some very well done CGI (particularly the super-power scenes) and an emotional score. Gong Yoo and Park Bo Gum both nail their roles, but the plot was lacking, and it failed to connect on an emotional level. The premise was interesting, but ultimately I was left feeling like what exactly was the point of the movie. I think the overall message of what it means to be human is decent, but I've seen it done better. I felt this was somewhat of a disappointment, as it had all the right elements but they somehow failed to impress. I think it was a decent watch but I wouldn't recommend it unless you are a huge fan of the lead actors and have nothing else to watch.

Former special agent Ki-hun Min (Gong Soo) is dying of a brain tumor, but when the company asks him to take on one more job, he agrees. It is necessary to move a secret specimen called Seobok (Park Bo Gum),a cloned being that scientists created in a lab with the aim of an immortal source of cures for all human disease. But such a valuable specimen draws the interest of many, many other entities, and Ki-hun is charged with protecting Seobok from them, if he can....

I've read a lot of science fiction in my time, and some of this reminded me of "Beggars in Spain," Nancy Kress's meditation on what a "super-human" strain of humanity could mean. It also reminded me (especially toward the end) of "Carrie." Also a number of men-on-the-run action films, and a more nuanced thought-piece about Things Man Was Never Meant To Know. A bit all over the map if one takes each of those threads separately, but I felt it all held together quite well, in large part because of the excellent acting of the two leads, who believably inhabit the psyches of a dying, regretful man and a manufactured but longing adolescent. Very poignant in the end.

Plot uses the currently popular & controversial cloning of animals; human in this case. Oh, plant cloning is OK. Cloned human, for some unexplained reason, is immortal and further unexplained are his special powers. That's sci-fi for you. The usual evil government corporate interests want to possess our handsome clone. Story is basically our clone is discovering what humans are really like at his own peril.