\[ \boxed { {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) =-x/2+1+x\sqrt {{x}^{2}-4\,x+4\,y \left ( x \right ) }=0} \]
Mathematica: cpu = 0.182023 (sec), leaf count = 34 \[ \left \{\left \{y(x)\to \frac {1}{4} \left (-4 c_1 x^2+4 c_1^2+x^4-x^2+4 x\right )\right \}\right \} \]
Maple: cpu = 0.172 (sec), leaf count = 24 \[ \left \{ {\it \_C1}+{x}^{2}+{\frac {1}{2}}-\sqrt {{x}^{2}-4\,x+4\,y \left ( x \right ) }=0 \right \} \]