It's a Decent Debut, but nothing special
The choreography is not terribly impressive and they're not strong enough in their movements to really pull it off. They have talent, but whether it was nerves or fatigue or both, they just don't have very much oomf here (the camera shake effect conceals most of it pretty well though, good job post-production people, good job). And with the lack of a visual story, it kind of stands out. The slow-mo solos are each interesting, but there's not enough in them. Rather than demonstrations of personal skills (like martial arts, dancing, or even just stunning good looks) they're all vaguely thematic but not terribly engaging. You don't get to learn anything about the members from them (nor do you get names. I like names. I'm a huge fan of names in videos, especially debut videos).
I love the bridge, everything from 2:42 to about 3:06 is spectacular. It completely negates everything I just said about the choreography and their lack-luster performance of it. Musically it's the most interesting and worthwhile part of the song. Around 3:10 it falls back to it's previous state of 'meh, not bad' but the lingering appeal of the bridge makes it feel less trite. The whole song is musically blah, but the bridge adds just enough spark to make it worth listening to.
All in all, it's a decent debut, not exactly solid ground to stand on, but nothing they can't recover from.
I was seriously impressed with the bridge, & I hope to high heaven that they deliver something more like it for next time. They have potential, but they really don't get to show it in this MV.