There are many things I noticed in the first mega level:

• Using Master keys on the very first two doors to skip toward the next section, and many other places that you have to master all of those doors on the way
• Two Exact negative orange keys in a row while the second one is useless
• Pink key trap while the total number of pink keys and doors are quite large
• Negative Purple door that baits to flip using the flip key while there are still positive purple doors forward
• A blast door is required to saved for the final brown key
• and maybe more

With so many traps listed above, I think it is a very  counter-intuitive puzzle and is much harder than the second mega puzzle, Chromatic Monolith.