  Close galaxy flybys, interactions during which two galaxies inter-penetrate,
are frequent and can significantly affect the evolution of individual galaxies.
Equal-mass flybys are extremely rare and almost exclusively distant, while
frequent flybys have mass ratios 0.1 or lower, with a secondary galaxy
penetrating deep into the primary. This can result in comparable strengths of
interaction S between the two classes of flybys and lead to essentially the
same effects. To demonstrate this, emphasize and explore the role of the impact
parameter $b$, we performed a series of N-body simulations of flybys with
varying relative $b$ ranging from 0.114 to 0.272 of the virial radius of the
primary. Two-armed spirals form during flybys, with radii of origin correlated
with $b$ and strengths well approximated with an inverted S-curve. The impact
parameter does not affect the shape of induced spirals, and the lifetimes of a
distinguished spiral structure appear to be constant, 2 Gyr. Bars, with
strengths anti-correlated with $b$, form after the encounter is over in
simulations with interaction strengths $S\geq0.076$, but they are short-lived
except for the stronger ones with $S\geq0.129$. We showcase an occurrence of
double bar that survives for a long time in one of the simulations. Effects on
the pre-existing bar instability are diverse. There is no uniform correlation
between these effects and $b$, as they are secondary effects, happening later
in a post-flyby stage. Bulges are resilient to flybys, while dark matter halos
can significantly spin up in the amount anti-correlated with $b$. There is an
offset angle between the angular momentum vector of the dark matter halo and
that of a disc, and it correlates linearly with b. Flybys remain an important
pathway for structural evolution within galaxies in the local Universe.
