Just finished playing this!
I must say, the sound effects were absolutely amazing! I was always joyed when I would find a secret area!
The level design, i.e the path which the player had to follow was good as well! I liked how you walked around the the inside-out bug in SW2.
Just a few things to note though.
Try adding a little bit of variety using different textures for the walls and floors as the level progresses.
If you can, try to slice the level down into a couple more levels, making it run faster on systems. SW2 isn't able to handle many enemies at once, and as a result, the framerate suffers when you add more characters than it can handle.
Also try to shrink the width of the frames, making the world more visible, because I felt a little claustrophobic in my play-through. Try shrinking the size of the bottom frame, to make it more unified with the rest of the interface.
Oh and a tip. If you can, try to make the levels in another editor, like Blender3D or 3DS Max, as long as you can group each object in the world with the material that it is applied to. That way, you can have a plane as a floor, rather than having 50 floor tiles in SW2, making the game have a higher level of detail. This way, you can populate your levels more, while having a world of the same size or larger!
Keep up the good work! Nice to see someone, other than myself, using SW2!
P.S. If you do consider using a different editor to make the levels and are need of some help, just shoot me an email!