PDFs are the most annoying filetype ever. Don't use it, like, ever. Also, why in hell do we need to use another .zip extractor, anyhow? Just make a normal .zip. Compression isn't that much better, especially with all the OGG files you've jammed into there. I'd suggest taking all the music out until you're ready for a full release, so you can allow people to test without such a large download. If the music is that important, include it as a seperate file like a lot of the bigger WADs have been doing. That way people don't have to download a 19 MB file just to play your stages.
In terms of level design, it was a major mixed bag. There were sections I truly enjoyed, like the fighting of syns in the dark, and the 4th map really was quite fun, but I sense a major issue in the entire level pack:
Buttons suck. Mazes suck.
We've already established that Castle Eggman is rather dull because of the overuse of buttons. Especially the first level was just a tedious searching of the exit by randomly jumping on everything. I just don't find that fun. I'd much rather run or fight enemies than jump on everything that happens to be higher than the surrounding terrain.
In terms of mazes, there were a few stages I simply couldn't find the exit to, and just gave up. I don't enjoy walking up to a blocked door, and then having to search the stage for anything resembling a button by turning around. Likewise, I really don't like it when I can't even find a path I'm supposed to be going on, like MAP06. I don't mean because of the darkness, I could see the paths mostly okay, and I liked the dark. However, I couldn't find any routes and just walked around in circles. After a good 5 minutes of this, I just used NOCLIP and walked through the wall that I knew led to a turret. I don't consider any map that I have to cheat to find my way out of the opening room to be fun.
I'd really suggest trying to do more traditional level design, with minimal buttons and more straight-forward level layout. Just because your theme is weird doesn't mean you have to have subpar level design.