  $\alpha$-cluster excited states in $^{32}$S are investigated with an extended
$^{28}$Si+$\alpha$ cluster model, in which the $^{28}$Si core deformation and
rotation, and the $\alpha$-cluster breaking are incorporated. In the GCM
calculation with the extended $^{28}$Si+$\alpha$ cluster model, the
$\alpha$-cluster excited states are obtained near the $^{28}$Si+$\alpha$
threshold energy. The $^{28}$Si core deformation and rotation effects, and also
the $\alpha$-clusters breaking in the $^{28}$Si+$\alpha$ system are discussed.
It is found that the rotation of the oblately deformed $^{28}$Si core gives a
significant effect to the $\alpha$-cluster excited states whereas the
$\alpha$-cluster breaking gives only a minor effect.
