You know, something that should be obvious but i don't think gets stessed enough is how important getting a good composer for the holo songs is. Smile and Go sounds painfully generic, and not in a good way, and i don't think Flare had any control over it being that way, really. In contrast, Gura's song is so cool. It clearly establishes a "storyline", by having the cover art be two contrasting sides of her character, and having the first line be ominous-sounding Greek. Then it uses these almost horror-like violin parts to further play on it. It's a playful, energetic song, that also has a great deal of personality to it.
The synth in this part is so good, agressive and ominous, the entire song really plays into the "deep-sea predator" thing while also being satisfyingly catchy to listen to. Or if you want another comparison, just lisent to Suisei's Next Color Planet, which has RIDICULOUSLY good instrumentation that brings the song to a level that honestly i feel is unmatched by any other holo songs. Going back to Smile and Go, if you want to make a very anime-opening sounding song, which seems to have been her intention, the importance of a good composer can also be expressed here, since Pekorandombrain accomplishes the same goal MUCH more sucessfully.