\[ \boxed { 2\, \left ( y \left ( x \right ) \right ) ^{3}{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +x \left ( y \left ( x \right ) \right ) ^{2}=0} \]
Mathematica: cpu = 0.007001 (sec), leaf count = 55 \[ \left \{\{y(x)\to 0\},\left \{y(x)\to -\frac {\sqrt {4 c_1-x^2}}{\sqrt {2}}\right \},\left \{y(x)\to \frac {\sqrt {4 c_1-x^2}}{\sqrt {2}}\right \}\right \} \]
Maple: cpu = 0.015 (sec), leaf count = 37 \[ \left \{ y \left ( x \right ) =0,y \left ( x \right ) =-{\frac {1}{2} \sqrt {-2\,{x}^{2}+4\,{\it \_C1}}},y \left ( x \right ) ={\frac {1}{2} \sqrt {-2\,{x}^{2}+4\,{\it \_C1}}} \right \} \]