The silver lining of the election outcome is that the extreme left and center parties have to form a coalition. Even if they manage to formally do that there'll be constant struggle and several such alliances failed across Europe recently.
Macron's interior minister already said he will not support a coalition with the far-left and greens. If that happens he'll be the first to sign a vote of no confidence.
Meanwhile the far-left is organizing a march on the seat of the prime minister in Paris to force Macron to be put in charge of the new government.
For added lulz: some in the socialist German party SPD warned against far-left leader Mélenchon and called him "nationalist, anti-Semitic populist" and "anti-European".