Physical vapor deposited transition metal carbide (TMC) based thin films are known to form nanocomposite microstructures comprised of nanocrystalline metal carbide grains embedded into an amorphous C matrix. The structural and mechanical properties of NbC films are strongly influenced by the carbon content determined by the C/Me ratio and the morphology. Here, we employed high power pulsed magnetron sputtering (HiPIMS) to deposit extremely hard NbC thin films and investigated the influence of the deposition parameters on the microstructure, mechanical properties and fracture behavior. Through tuning the HiPIMS pulse parameters (ton, f), a variation in the target power density from 0.17 to 1.2 kW/cm2 was achieved. This wide variation allows for a control over the stoichiometry, as well as the microstructure of the NbC films, that leading to a wide variation range of the mechanical properties. A time- and energy-resolved mass spectroscopy analysis of the ion fluxes was employed to explain the observed changes in film composition and mechanical properties.