I liked this pack.
The course design was generally nice and enjoyable. I liked the pick-up-and-play feeling it has.
Some of the ideas were pretty neat, such as the "sloped" sand that leads into pits, the fake floors, and the climbing areas. I liked the course in Sky Castle with the tower that you climb, the one where you go around little curves that slope into pits, and the half-pipe ones in particular. The bouncing-off-walls-over-pits idea was enjoyable as well.
I liked the shortcuts you put in the level, as they add replay value.
The levels were a bit on the easy side. A lot of the early ones can be gotten in one shot, and I've actually managed to do it on some of the ones in Detritus Desert (which I assume is based off of Monkey Ball). Moving objects and more "slopes" would be cool and can add more difficulty.
The music used was nice but I thought they were unfitting. The desert in particular had an unfitting song because it doesn't have the "wide, endless desert" feel that Super Monkey Ball did, which made the music fit so well in that game. Turquoise Ocean didn't capture the "big ocean" feel the Monkey Target song carries, and Sky Castle didn't feel very haunted.
The scenery was a bit lacking. Adding more hills and islands in the background can make things feel more expansive, because, as of now, things feel pretty closed-in. Things didn't feel very atmospheric and felt bland sometimes because of this. More texture variation and Thing scenery could help.
The boss courses were pretty lame. It's even more repetitive than the usual boss fight would be, so I simply didn't bother with them and skipped them. I'd recommend removing them.
Overall, this course has some nice designs and hazards, but it's a bit too easy and lacking in scenery. I recommend removing the bosses. I'd also like it if you had the "Zones" go for eighteen holes.