I'll start with the bad, Parts of it is so generic that it feels like I've seen it before. The bedroom parts and Sanas face close-ups are very uninspired (even though she is still pretty), they're almost exactly the same as previous MVs.
The school scenes are a mixed bag, bullying by other group members is a fun concept they could have expanded more on. The transsexual theme is as abhorrent as always. I'm very disappointed to see that jungers once again is forced into cosplaying the opposite gender when she has been feminine in the last couple of comebacks. This meme is very tired and has been overdone before twice even existed. They could have made it a bit interesting by only having the other members as semi-transsexuals in the couple dance scenes and leaving Jung as a female, but they did not.
The couple dance scenes are rather refreshing, And I would say the first one is the best part of the MV. The camera angles give the scene a interesting flow not usually seen in kpop. The poor CG on the background combined with the style and dance gives the scene a interesting old-school vibe as well. The second couple dance scene is a reference to the movie La La land, which made me realize there's many more references I'm missing.
The MV is actually mostly references, much like cheer up. Opinions on this is going to vary, some will love it, but I believe this is objectively true: Using references and established themes instead of creating more original content is a easier way to get viewers interested by using things they already like. Personally I don't enjoy the references, as I am not interested in (older) pop-culture movies. Had it been references to something dear to me I would surely have loved it. I'm also not sure how much credit I should actually give to the MV, since I don't know how much "inspiration" it gathered from its references and how much was arranged by JYP.
There is a literal ad part of the video, introduced by two other TV-themed scenes. Not a mere product placement which is fairly common. I'm sure this paid very handsomely, but I see it almost as a reference to momoland's Bboom bboom which has a full theme of TV shopping. Perhaps momolands first successful song has unintentionally paved the way for full-blown ad segments in kpop music videos. Despite the unoriginality and obviously commercial intentions behind this scene it is one that I liked more than the rest of the mv.
The actual technical video quality is low as usual. The video is in a 21:9 aspect ratio, pointless as it's not going to be viewed in a cinema and then squeezed into a 1080p resolution. This is of course the standard procedure for kpop but I'm still going to complain.
I'm really not sure what to say about the song. The intro was a bit different from usual, I liked the cuckoo sound but now I am questioning it's symbolic meaning. I was hoping for the song to include some new sound, like the bassline and synth in the intro but I was mostly let down. Other then some synth bits and the trap-beat which both make brief appearances it strictly follows the twice formula. If you wanted more twice songs that sound like twice, you must love it.
If I was to pick a favorite part of the actual song, it would be the rap part. It's catchy, goes well with the MV and I'm glad to see dubu as a actually feminine female rapper. As per usual, dubus rap is significantly better than Chaeyoungs.
It's not bad. It's well made, it just seems like something you have already heard.