I'm glad I stumbled upon it when I was still half asleep. If not, maybe I won't click it. 
AND I'LL REGRET IT FOR MY WHOLE LIFE. Okay maybe I'm exagerating

But seriously though, I really like it! 
I was afraid that it was going to be too cutesy for me (like apink or something...), but it turned out to be much more better than I imagined it.
The song is nice and catchy, fitting for the summer months. One more song added to my playlists of 'summery song to help me get ready in the winter mornings'. The rap is nice, but the second verse/bridge is my absolute favourite part. 'Happiness!!' lol it's really catchy I love it.

Okay now more critically. The song gives me some f(x) vibe, especially in the part at the beginning. Maybe it's just SM trying to ease us in by not BAM new song NEW STYLE FOR YOU. 
There's so many things happening in the MV! But I like the sequence where that one girl get into what... static imprints of her? wtf I'm talking about... you know what I'm talking about if you watched the MV. I really think the effects gave an edge to the MV, and the jungle theme is nice too, even though it looks so painfully fake... 
But their hair... WHY... It looks... No [[EDIT: After some consideration... Now I think that 'hair color coding' is such a brilliant idea. I'm super bad at distinguishing faces but now I can just go 'who's the green haired one? Oh, Joy.']]. But really, with the hair, the song, and the MV look, they all reminded me of f(x)'s Danger. Not saying that it's a bad thing here ok.
And also I just realise something. OK I know the rookie videos also acted as this group's teasers (even though not blatantly written as such), but compared to EXO? Well, this one felt a little abrupt, doesn't it? Or maybe they do release some introductory pictures and it's just me who's not up to date enough? Or maybe SM realise that their marketing strategy for EXO debut was a bit stupid (TEASER #24601) and learned that maybe being concise is better.

THE BEAR THOUGH. 
The ditto bear gloop is so cute omg please SM you make merchandise out of everything. MAKE THE DITTO BEAR THEIR MASCOT. Please! I want the plushie T^T.

Sooo please watch the MV! Like it, favourite it, watch it several times, make covers of it, SHOW THEM LOVE. That's just common sense, you know, to show some respect, especially to people who's just starting out on their journey. Critics are fine. But all out bashing? Please. You know better.