After investing longer than 16 hours, as a sci-fi fan, all I can say that the drama started with a bang. The opening was mesmerizing especially with the impressive acting of Kwan Si Yang. He outshone the male lead and the female star every time he appeared on the screen. However, after the 6th episode, viewers are hesitant to go on watching as it is not clear whether they are watching the multiverse or the butterfly effect of the time travel as these two things seem to merge into each otherin the drama but they are different aspects in theory. The importance of the family bonding especially mother-son relationship takes so much time that some audience may find it repugnant to see the over emphasis on the romance between Tae yi and Park Jin Gyeom, mother and son in another time line.

If the script were written a bit more meticulously with a solid background of physics and some logic, the drama would have been very inspiring and aspiring. However, except for the acting skills of the main leads especially the top notch acting style of Kwak si yang, who wonderfully expressed the anger , sadness and frustrations of a father in micro details, there is nothing to recommend about the series. It is such a pity that a good opening which had the potential to have sparks on many fronts such as sci-fi, fantasy, alternate universe, multiverse, family bonding, present versus past lives sizzled so much that even the ending came out as non sequitor as to why after the reset it is only Tae yi who has not lost memory but the others all forgot everything in this new alternate universe. In order to have an open ending, the director and scriptwriter wasted both the talents of the actors and storytelling.