I haven't heard any issues with the music, but there's five hours of material there to listen to so there could be problems I haven't heard. So far, I love the way you've handled converting the dynamic music, and the ridiculous amount of new material included just for this format. I have mixed feelings about the mid-track transition for 'Having Fun Fun Fun Fun Fun', specifically the abrupt stop to the background noise, but I'm guessing it is as you intended.
The cover art is very nice, I especially like that there is a unique (and appropriate) image for each folder.
Here are some mostly personal issues I have with the tagging:
- Berliner Bratwurst, which is Track 13 of Folder 3 (Upbeat), has the artist and title fields reversed in the tag. The filename is correct, though.
- I saw you talk about this on Twitter already, but for compatibility with MP3 players, you should assign an Album Artist to all tracks that is the same for every track. If you don't want to use 'Nicklas 'Nifflas' Nygren' for tracks you didn't create, you could instead use something like 'Nifflas & Friends' or 'Nifflas' Games' for every track.
- Also with MP3 players in mind, I think it could be preferable to set the album field to just 'Knytt Underground' for folders 2-6 so that it is the same for all 121 tracks, and make use of the 'Disc #' field to indicate with folder a song is from. The format I have most often seen used for this field is 'CurrentDisc#/TotalDisc#'. For example, 'Fast Travel Inside Dreams' would retain the track number of '02', but additionally contain the disc number '5/6'. This would hopefully ensure all the tracks are grouped together but in the correct order... perhaps you wish to distance the other folders from the main soundtrack, but I feel the current method is kind of cluttered. No problems if you decide this method is not for you.
I will continue to listen, and report anything else I think of!