I believe what you’ve put in does belong. I’m still learning series myself, but there’s so many things that a series can be, such as:
- iTunes Single of the Week: a free music promotion that ran for several years.
- K-ON!: all of the soundtrack release groups for an anime.
- Lady Gaga Parody Trilogy: a series of loosely connected songs, but the artist specified it was a trilogy.
- Mandatory World Tour: tours are a special type of event series.
- Star Wars: I’ve even seen series for franchises like this. (granted, I made this one, but I’d seen this kind of thing done elsewhere)
- 20th Century Masters: The Millennium Collection: a series of “Best of…” release groups, released by Universal Music Group.
these are just some more examples off the top of my head.
as to the title of your series, if there’s an official title, of course use that. otherwise, I’ve put an unofficial title in brackets, like with [Mouth Music]. in this case, maybe [Final Fantasy] with “$WAGGOT” as the disambiguation? I leave that up to you, as you’re familiar with the series. 