A detailed kinematical analysis of wind-blown bubble ring nebula NGC 6888 swept-up by the wind of the Wolf-Rayet star WR 136, combining high resolution echelle [O III] spectra, high resolution HST imaging and high resolution ground base imaging, is presented. The kinematics is compared to new theoretical models for the dynamics of WR bubbles based on a three-winds scenario. The actual visible nebula is formed by the red supergiant wind swept-up by the fast WR wind. We conclude that the intringuing filamentary morphology, mainly formed by clumps, tails and ripples are explained by the actuation of Vishniac instabilities on the swept-up shell during the expansion of a red supergiant wind, as predicted by the gas dynamical simulations. The kinematics confirm that NGC 6888 is actually on a breakout process at the NW side, as derived from the blowouts. The blowouts are formed by shocked gas which is directly interacting with the cavity formed by the main sequence wind. The fact that these blowouts are bounded by shocks suggests that the cooling is efficient in a main sequence bubble during the evolution.