Okay, say when I kill an enemy, while its dying I want the frame rate to slow down just to add that extra oomph.(Noitu Love 2 style) Then when nothing is dying I want the frame rate to go back to normal. You know what I mean right?
this can cause some ugleh slow frame rates (no duh)
A much more complicated, but smooth technique is to have all movements, turning and animation speeds based off a global speed coefficient, which can be modified mid runtime.