After rendering, every item must be worked over.. in rendering, to make the things look good, their border "mix" with the background color. You have to rework it so that this border does not show (and the graphics still look good). That's pixel-work. And every moving figure has 16 graphics (they must fit exactly) : 4 for every direction.
As you can see that takes some time =)
And to make a complex figure in 3d, well, i am playing with a dragon shape, and that for several hours - and it still lacks arms and legs, as well as wings.
You can download blender at
http://www.blender.nl, it's size is about 2 MB. There are several tutorials too.
The most powerful tool, or one of the most powerful, is the extrude function, in combination with scaling. You can make whole figures with that. Then you need 4 cameras, in a matching perspective (one ground square must look loke a floorplate, twice as wide as high).
Since blender is a free tool, has online tutorials in almost all functions, and will be developed further too, you have no excuse not to try it out a bit. But be warned, blender is complex. But with the starting tutorials, and a little time, you can work into it.
So you have no excuse - start making cool graphics now.