Well we can't complain about the new stage itself, because it's brilliant and unique.
The song selection, though, is lacking variety. There's SO, SO MANY good songs from all Donkey Kong Country games, yet they decide to keep doing variations of Jungle Hijinx. Not that the song isn't good, but it feels ignorant to ignore the all other great tracks. :/
They took 5 versions directly from previous games (Smash 64, the 2 from Brawl, DKCR, DKCTF) and did two new remixes on top of that. I think the two new remixes are done by the same composer too, unlike the two versions from Brawl.
But that's not my gripe with the soundtrack. My gripe with the soundtrack is... well, take a look at the following list:
- Kongo Jungle 64
- Jungle Level (Brawl)
- Jungle Hijinxs (DKC Returns)
- DK Rap (Melee)
- Main Theme (Metroid) (Brawl)
- Brinstar (Melee)
- Pollyanna (I Believe in You) (Mother) (Melee remix)
- Id (Purpose) (Fire Emblem: Awakening)
- Crimean Army Sortie (Fire Emblem: Path of Radiance)
- Gaur Plain (Xenoblade Chronicles)
- Gaur Plain (Night)
- Engage the Enemy (Xenoblade Chronicles)
The common denominator of those songs: they aren't the full versions, but shortened versions with parts removed. Another common denominator: originally had loops of over 3 minutes.
This detail in musical direction leaves me displeased.
You can also add to that list the Sonic vocal main themes, though those also had the same fate back in Brawl.