haha. The first part in making stuff appear 3d is to visualize the sequence happening in a real space, so your state of mind is that it is in a real space. Thats atleast a good state of mind to be in since flash is a 2d program, so basically, I am fooling you into thinking something that is 3d, is actually 3d.
For the moments I think you are wow'd by where I do camera shifts and stuff, the first one is a frame by frame of me manipulated the background, as well as redrawing pico each time...so yeah, that was frame by frame. Thats why it has a little shakey feeling to it. That took a long time to do, so i then just started using well placed tweens, which look 3d if you move them right. A better example of that kinda thing is in my latest animation Nuts where I move trees around in a such a way that it looks like a 3d space.
This cartoon has a lot of stuff in it that I still use in my current animations(for instance I kept using bitmap backgrounds in this). This cartoon was a huge step in my own growth since I did so much stuff I hadn't done, or even attempted. Sadly its not that visually apparent compared to others.
So yeah, If you wanna see better 3d in animations i've done, go watch Nuts, or Jedi vs Ninja(though that one doesn't have as much).
Oh yeah, and the bad guy whenever he turned was actually a tween, each part of his face was a symbol and i just manipulated it correctly so it looked like he was turning, flash sure is wonderful sometimes.