\[ y'(x) \cos (y(x))-\sin ^3(y(x))+x \sin (y(x)) \cos ^2(y(x))=0 \] ✓ Mathematica : cpu = 0.489369 (sec), leaf count = 61
\[\left \{\left \{y(x)\to -\cot ^{-1}\left (\sqrt {e^{x^2} \left (-\sqrt {\pi } \text {erf}(x)+4 c_1\right )}\right )\right \},\left \{y(x)\to \cot ^{-1}\left (\sqrt {e^{x^2} \left (-\sqrt {\pi } \text {erf}(x)+4 c_1\right )}\right )\right \}\right \}\] ✓ Maple : cpu = 0.534 (sec), leaf count = 55
\[y \relax (x ) = \arcsin \left (\frac {1}{\sqrt {1-\sqrt {\pi }\, \erf \relax (x ) {\mathrm e}^{x^{2}}-2 c_{1} {\mathrm e}^{x^{2}}}}\right )\]