  Superconductivity with a remarkably high $T_c$ has recently been found in
Sr-doped NdNiO$_2$ thin films. While this system bears strong similarities to
the cuprates, some differences, such as a weaker antiferromagnetic exchange
coupling and possible high-spin moments on the doped Ni sites have been pointed
out. Here, we investigate the effect of Hund coupling and crystal field
splitting in a simple model system and argue that a multiorbital description of
nickelate superconductors is warranted, especially in the strongly hole-doped
regime. We then look at this system from the viewpoint of the spin-freezing
theory of unconventional superconductivity, which provides a unified
understanding of unconventional superconductivity in a broad range of
compounds. Sr$_{0.2}$Nd$_{0.8}$NiO$_2$ falls into a parameter regime influenced
by two spin-freezing crossovers, one related to the emergent multi-orbital
nature in the strongly doped regime and the other related to the single-band
character and square lattice geometry in the weakly doped regime.
