Very nice little collab you've got going here, I enjoyed it quite a lot. Personal favourite level was "Slightly Frosty Clouds".
It was mostly spot on for me, save for some very tight jumps and claustrophobic areas in "Wendy Returns." and some issues I had with time limits. Even though the time limit in "Tower of Koopalon" was about 600 seconds, I feel it could be still extended, as it didn't really give much room for messups with the fact the player can fall down and how there are some sneakily placed invisible blocks. Otherwise it was an amazing level with some great ideas behind it.
Also minor, but in "Psysix" in the water section, you can swim out of the level to the left until the timer runs out lol.
Very nice collab though, even if it is smaller than the previous ones. I enjoyed moderating it very much ^^
Good so far. On Funky, I died from time out while eating a berry, and the game froze. There is some patch that could be applied to fix this.
EDIT: well... average, boring design; nothing too creative was done. This was just quite uninteresting for me (I don't really like exploration, non-linear levels. Maybe others will have different opinions? Also, there was lots of boring backtracking and just simple platforming.) 2/5 I guess.