Super-Eddington accretion happens in various astrophysical systems. For example, it is currently believed that super-Eddington accretion onto neutron stars and stellar-mass black holes power a large fraction of ultra-luminous X-ray sources (ULXs). In this work, we conduct a series of 3D general relativistic radiation magnetohydrodynamics (GRRMHD) simulations of highly magnetized accretion flows around stellar-mass black holes. While similar simulations have been performed previously, a systematic investigation of how various physical parameters affect the properties of the disk and outflow has been lacking. Our results disclose that the gas accretion rate crucially determines the outflow-inflow ratio for such accretion flows, while both the gas accretion rate and the black hole spin control the energy output. Our results shed light on understanding super-Eddington systems such as ULXs. We address several questions, such as how luminous the X-ray sources can be, how beamed their emissions are, what determines the power of their winds and jets, etc.