The present experimental study, carried out on the Mascotte test bench of ONERA, aims at characterizing the flame and flow dynamics of a rocket-type combustor equipped with five shear-coaxial injectors fed with methane and oxygen. Backlit and OH* chemiluminescence imaging techniques are used for the characterization of the liquid atomization and flame dynamics obtained with three canonical cases labeled after the thermodynamic state at which oxygen is injected: gaseous, subcritical or transcritical, whereas methane is continuously injected at a gaseous state. For gaseous-oxygen operating conditions, a Low-Frequency flapping instability of the flame was observed and analyzed by means of the Spectral Proper Orthogonal Decomposition (SPOD) technique. For subcritical pressure, the atomization process is characterized by measuring the liquid core length and by providing a probabilistic description of the spray.