I honestly am confused on my feelings for this.
On one hand, it's massive. It has some fantastic songs in it. On the other hand, there are quite a bit of questionable choices that it really feels empty.
For example, I'm a kirby fan. I really love the more recent games like Super Star Ultra, and triple deluxe. Instead of getting very awesome songs from those games like Masked Dedede, Crowned, Moonstuck blossom, hypernova, super ability, etc., we get remixes of songs that were already remixed...And the songs we do get from the newer games are the standard beginning songs...
What makes it even worse is that Masked Dedede and Crowned are both fan-favorite and recurring songs in the main series games, it makes no sense not to include them.
Thats not even including the other characters like Game & Watch getting nothing, and Pikmin barely got anything but it isn't exactly special.
Oh, and while I'm not a DK fan, the DK songs really is one the worse things about the ost. :/
People complain that lots of songs are ported directly from their source games or Melee/Brawl when half of the songs in Brawl are ported directly from their sources too. Hugh. People are never satisfied. Sure, some iconic songs aren't here, but if they remixed every single iconic song, what would be left for future Smash games? Yeah, they would have songs from newer games, but then people would complain that we didn't get any remixes from classic games.
I honestly don't care if the song is remixed or not, the fact that they aren't there at all is what is disappoint about all of this.