The underlying equations are fairly simple equations on wave functions. They describe linear wave equations that evolve the wave functions over time. The dynamics is both deterministic and time reversible (with the appropriate CPT symmetry).
Maybe you are worried about it using complex numbers. But classical waves like ocean waves can be described with complex numbers, e.g. using the velocity as the Imaginary component.
Maybe you are worried about it using spinors. But classical waves like light polarisation can also be modelled with spinors.
Maybe you are concerned about objects that return to the same configuration after 720. But classical anti-twister mechanisms do this too:
Maybe you find it weird that everything is discrete. But it isn’t really, discreteness only arises from bounded states, like electrons bounded to a nucleus. Classical physics has this too, in standing waves.
Maybe you are worried about the uncertainty principle. But this isn’t a case of inaccessible information, it is a case of using inappropriate variables (position and momentum) to describe something that isn’t a point but a wave.
Maybe you are worried about entanglement, action at a distance and Bell’s inequalities. But these are issues for theories that have realism and separability. Several interpretations (including Everettian/Many Worlds) do not have separability, so nothing is non-local.
Maybe you are worried about spins being either up or down but nothing in between. But this is not quite right, you can get any superposition in a continuous range, and the spin-up and spin-down represent two different types of wave. You get the equivalent in classical physics with light polarisation.
It is in fact the simplicity (linearity) of quantum physics that leads to the superposition and the many worlds effects that cause headaches for physicists that try to insist on there only ever being a single branch of the universal wave function.