Aww Iove the colour scheme and the trotting is great!
The two sets of legs do work separately in a way.
They're supposed to transition the weight from the front of the back to the back and vice versa while
manipulating itself in a 3 dimensional environment.
The reason the walk looks weird is the body moves up and down as a whole. That may be the case
for bipedal creatures.. but not for this. When one set of legs reaches it's passing point (the highest
point the body will reach in animals), the other set should be at it's recoil point (taking the weight).
By doing this, you get a sense of see sawing with the animal. If done right you also include the
shoulder blade coming up and down for a really realistic effect!
Nice job though!
head is a bit static. also looks a bit like the two sets of legs are working separately, rather than all four together.
very neat!