  We consider the realization of N=2 superconformal models in terms of free
first-order $(b,c,\beta,\gamma)$-systems, and show that an arbitrary
Landau-Ginzburg interaction with quasi-homogeneous potential can be introduced
without spoiling the (2,2)-superconformal invariance. We discuss the
topological twisting and the renormalization group properties of these
theories, and compare them to the conventional topological Landau-Ginzburg
models. We show that in our formulation the parameters multiplying deformation
terms in the potential are flat coordinates. After properly bosonizing the
first-order systems, we are able to make explicit calculations of topological
correlation functions as power series in these flat coordinates by using
standard Coulomb gas techniques. We retrieve known results for the minimal
models and for the torus.
