We present an experimental work performed on a vibrated granular gas enclosed into a 2D-cell. Experimental investigations are performed in microgravity during parabolic flights. High speed video recording and optical tracking allow to obtain the full kinematics of the particles allowing the determination of all inelastic parameters as well as the translational and rotational velocity distributions. The energy input into the medium is performed by submitting the experimental cell to an external and controlled vibration. Two model gas are studies: beads and disks; the latter being used to study the rotational part of the particle's dynamics. We report that the free cooling of a granular medium can be predicted if we consider the velocity dependence of the restitution coefficient and that the experimental ratio of translational versus rotational temperature decreases with the density of the medium but increases with the driving velocity of the cell. These experimental results are compared with existing theories. We also introduce a model which fairly predicts the equilibrium temperatures along the direction of vibration.