Ah, I'm glad to hear these reviews.
On the Layout:
I think I missed it a bit as Pi said by simply not having enough Volcano walls in the middle section of the map, and also by making it more of a "labyrinth" than the actual Volcano is as Edwards pointed out. Although, I was trying to get it more like the Multi Player map than the Solo mode map, as I wanted it very free roaming, so the "labyrinth" style layout might not be too far wrong.
On the Difficulty
I'm glad I got that 'round about right. I know some corridors are more stuffed with fliers than others, but then so are the ones in Multi Player. I want it fairly easy so that new players can play it and get a challenge out of the layout, and more experienced players can still get a challenge by trying to get the best time after they've beaten it the first time. Oh by the way, what were your times guys? If it was around ten minutes or so I can feel accomplished. My best time is 4:24, but my average is seven minutes. (although that's because I have to keep stopping to admire the scenery ^_^ )
On the Enemies
Yeah, looking at it now in the editor I can see some nasties that definitely don't belong here. The Spinning Turrets for example, they should be almost excluded to the Factory. Would it be better if I got rid of Spinning Turrets, Bugs of all kind, Factory Crusher Things and Explosive Clusters?
On the Boss
Meh, I like the Boss. lol! Ok, so I need a better explanation: I was planning on having the real Bosses used in each level, as I'm kinda fed up with creating my own all the time and not many other levels use them. Plus, it would help maintain the feel of the levels if they contained some authentic features. However, I can change the Mini Boss if people would like to see something new, and I can still try to maintain the Volcano element to make it fit right into the level.
Thanks for playing the level guys, and thanks for giving me your thoughts. I'll wait a little while for a few more people to comment, and then I'll post up an updated version.