Nucleon-nucleon and symmetric nucleus-nucleus collisions are studied in a wide range of centre-of-mass energies. Phase space distributions of pions and ka~ns are characterized by the widths of the rapidity distributions and their average transverse momenta. The shapes of the rapidity distributions are found to dependent rather on the energy than the mass of the projectiles. At a given energy it is independent of the longitudinal phase space distribution of the participant nucleons in the final state of the collision. The average transverse momenta of pions are insensitive to projectile energy above x/~ of 10 GeV and increase only by a few percent when going from nucleon-nucleon to central nucleus-nucleus collisions. The average transverse momenta of heavy particles produced in hadronic interactions saturate only at higher beam energies. Their system size dependence is considerable. In central nuclear collisions at x/~ of 20 GeV mean transverse momenta in excess of what has been obtained in p+~ at v~ of 630 GeV are found. In central A + A collisions the inelasticity rises with beam energy in contrast to an approximate invariance in nucleon-nucleon interactions. The fraction of energy in strange particles increases with energy up to V ~ of 5 GeV and saturates beyond. A similar behaviour is seen as function of projectile size. A strong increase of the energy fraction in strange particles from nucleon-nucleon to central collisions between light nuclei like sulphur contrasts with a minor increase when comparing light with heavy nuclei.