  We present simulations of the intermediate state of type-I superconducting
films solving the time dependent Ginzburg-Landau equations, which include the
demagnetizing fields via the Biot-Savart law. For small square samples we find
that, when slowly increasing the applied magnetic field $H_a$, there is a
saw-tooth behavior of the magnetization and very geometric patterns, due to the
influence of surface barriers; while when slowly decreasing $H_a$, there is a
positive magnetization and symmetry-breaking structures. When random initial
conditions are considered, we obtain droplet and laberynthine striped patterns,
depending on $H_a$.
