Quick example showing how you can achieve non-linear movement which is constant at any framerate.
The sprite chases the mouse cursor by closing in a certain percentage of the distance remaining every tick. Since it uses TimeDelta, it works the same rate at all framerates. Try it - fixed 10fps or unlimited, even with a hundreds of times higher framerate it still goes at the same rate.
Just thought I'd share it, because the formula is a bit tricky to work out otherwise Also a good example of interesting places to use lerp().