This is an amazing level, but towards the end problems with challenge design spoiled a big part of the fun.
Linear structure of the level (with the exception of the starting area) and inability to go back (despite what's incorrectly said at x1027y1001) don't facilitate collecting golden creatures well.
Could you upload the last version made for KS Ex too? I'd like to play it with a ball too.
x1008y994 - invisible killing tiles
x1032y987 - ledges in the tower could use jump-through platforms
x971y1026 - autosave shift
x1021y965 - must have save point! At a point before you get killed by an invisible small black spider. Overall this area has bad challenge design all over it - lots of surprise deaths due to lack of vision and the random spewer at x1021y966 with its projectiles completely blocking the way when you're unlucky. Random creatures added to challenges that would be fair otherwise are the problem in a number of other screens in the level as well.
x998y970 - was this screen supposed to have water physics like the others?
x998y966 - need a save point at 12y8.
x1024y965 - if you jump down here after getting the double jump, you have to go through the whole transformer again.