Another World was rotoscoped, not vector.
Just search Aminet for structured drawing packages.. there used to be loads of them.
I once wrote a simple polygon rendering engine, to test an idea I had for a game... No curves as the bezer maths was too boring to figure out... All the test models I made were build from triangles. One innovation I did, was to include a skeleton structure which allowed each vertex to be related to any other... got bored with though... 3D gfx were getting popular by then.