They were indeed just a bunch of maps I made. I called it a mini campaign because it couldn't really be called a campaign do to no dialogue and such.
As to level design. I wanted to try something new instead of standard boring stuff. Many levels were so SHORT you didn't even get to wander around and enjoy the scenery. A few thwacks and poof, on to the next. That got boring quick. No skill to get around most levels required. I admit that platform jumping is annoying in 3D games and is the usual skill required, so I tried to avoid some of that with unusual design. Work or not, it was fun but frustrating.
I loved cave maze, but yes, view distance was shortened do to... I have no idea. It seems to start on that view distance and I just left it at what it was. As far as I know view distance has a default and isn't saved between levels.
It was amusing turning the engine upside down to do things, or at least the trees. Be happy I didn't include Hard Climber : ) How was Collapsed Valley with the trees constantly blocking your view? Now THAT'S a forest!
3D maze wasn't finished, I just ran out of objects that could be placed. It was huge and fairly frustrating anyway to find the enemies in. would be less so with more enemies to bop.
I greatly enjoy Spiral Stair's design, though again, too few enemies available to fill it.
Block Ruins was another favorite of mine
Multi-level... was an experiment. It wasn't very fun to play through despite there being a variety of designs in it. I shouldn't have used the chimney's to go up levels especially. A simple ramp would have been a better choice. The enemy at the end is overpowered to a degree(not as bad as Evil Twin), and even I have never played through it fully fairly.
I left out a very simple map called Fire Maze, which was just a maze made out of fire fields. It worked ok, but was pretty easy.
Make more levels? I started to make a Cave Maze 2, but I keep hitting clipping errors that ruin it. It's such a pain in the ass to make levels in that game with having to move Turner around and TRY to position them correctly :/
I'm glad you liked and took the time to actually say something about it.