  The repeating fast radio burst source FRB 20220912A was remarkably active in
the weeks after its discovery. Here we report 696 bursts detected with the
Nan\c{c}ay Radio Telescope (NRT) as part of the Extragalactic Coherent Light
from Astrophysical Transients (\'ECLAT) monitoring campaign. We present 68
observations, conducted from October 2022 to April 2023, with a total duration
of 61 hours and an event rate peaking at $75^{+10}_{-9}$ bursts per hour above
a fluence threshold of 0.59 Jy ms in the $1.2-1.7$-GHz band. Most bursts in the
sample occur towards the bottom of the observing band. They follow a bimodal
wait-time distribution, with peaks at 33.4 ms and 67.0 s. We find a roughly
constant dispersion measure (DM) over time ($\delta$DM $\lesssim$ 2 pc
cm$^{-3}$) when taking into account `sad-trombone' drift, with a mean drift
rate of $-8.8 $MHz ms$^{-1}$. Nonetheless, we confirm small $\sim0.3$ pc
cm$^{-3}$ DM variations using microshot structure, while finding that
microstructure is rare in our sample -- despite the 16 $\mu$s time resolution
of the data. The cumulative spectral energy distribution shows more high-energy
bursts ($E_\nu \gtrsim 10^{31}$ erg/Hz) than would be expected from a simple
power-law distribution. The burst rate per observation appears Poissonian, but
the full set of observations is better modelled by a Weibull distribution,
showing clustering. We discuss the various observational similarities that FRB
20220912A shares with other (hyper)active repeaters, which as a group are
beginning to show a common set of phenomenological traits that provide multiple
useful dimensions for their quantitative comparison and modelling.
