Sure! I'll help with some voxel stuff.
The thing is... If AppGameKit is like DBPro is... in DBPro there are a bunch of extra lines for debugging and stuff for each line of code written (or that's what I've heard), and so the time needed for heavily looping stuff like this is a lot longer. This uses matrix multiplications and transformations, which are math-intensive. I could definitely help with a stripped-down version of this kind of math!
Also, 4d is really confusing. With normal rendering you can just be like "Oh yeah, if I rotate it like 80 degrees on the z axis I can see this cool looking part of the object". In 4d... Things are waaaay different spatially. One of the first things you have to account for, is that in 4d rotation isn't defined around an axis, only around a plane. If an object looks like it's morphing, it's really not, it's just rotating and moving in the fourth dimension!
In 3d, if an object is infinitely far away, you can still say "it's in that direction". If you had a 2d screen looking at an infinitely far away point, and rendered that point as a dot on the screen, you could have a dot in the middle of your screen. So then... Say you had one of the left two objects on your 3d screen. If you saw the object shrinking and shrinking until it's just a point, then all it's doing is getting further away from you!
It's creepy seeing the parallels between a 2d object rotating in 3d space, and a 3d object rotating in 4d space. There are some good images
here.
Also, that shape I'm drawing in the top two (called a julia set), is defined by iterating the function Z=Z^2+C, where C is constant, Z is a complex number, and the first value for Z is the coordinate in space you're checking. So lets say you start out with some coordinate Q, you get:
Z=Q (iteration 0)
Z=Z^2+C (iteration 1)
Z=(Z^2+C)^2+C (iteration 2)
Z=((Z^2+C)^2+C)^2+C) (iteration 3) etc.
so after a certain number of iterations, if Z's length keeps getting larger and larger, that original point, Q, is NOT part of the julia set. If it stays bounded (IE always close to the origin), then Q IS part of the julia set.
The thing that's really cool is... Well, usually people just use complex numbers as Z=a+bi. With some stretch of the basic principles of math, you can create a 4d "quaternion", Z=a+bi+cj+dk, where i j and k are all imaginary constants. There's also a higher dimensional thing called an "octonion", that has 7 constants. So, you can plug in complex, quaternion, or octonion number equations in the equation, and still get a cool shape! (eerrrrm, there are a bunch of mathematical implications... but all I know it as is a cool shape. derp.)