"Youkai Watch Music Best -First Season-" is, as the title shows, the first best album of Youkai Watch; a popular series of role-playing video games and a mixed-media franchise. It consists of all the songs used at the movies, TV anime and video games from 2014 to 2015. The sequel to this, "Youkai Watch Music Best -Second Season-" was released in 2017 summer, by the way.
I believe that this best album was released so timely, because "Youkai Watch" had already passed the freshness date. If they postponed the release more, it is easy to guess that it would be worse.
The best time of "Youkai Watch" is considered to be 2014 when the "ゲラゲラポーのうた" got so popular all over Japan. In the end of 2014, we were so easy to hear those songs from Japanese TV music programs. However, it was more difficult in the end of 2015. "アイドルはウーニャニャの件" was published in collaboration with AKB48, a Japanese popular female idol group. But the song is hardly known among the general public.
Then, I can say timing of the release is very timely. Admirable are the record company and the producers who judged so.
I have nothing to mention about musical points of the best album. I believe it is nonsense because the songs are, good or wrong, perfectly based on "Youkai Watch." When you are trying to catch up the "Youkai Watch" in the musical aspect, the best album will surely work.