That looks great to me. However reconsider the way you're doing shadows below the feet of the spites, it looks like they've chained their feet together instead. I'd rather no shadow at all to this.
The cracks give it a cool style. This is great progress I think.
At first, I just had a black shadow but I found it a bit too strong and swapping it with another colour wouldn't work to well as I may have different coloured grounds for them to fight on and the colurs might clash. Also, with a thicker shadow - when the srites come into contact with each other, I dont want the shadow of one sprite interfering or covering another too much, but this wont look so bad with the dither shadow.
Without a shadow it just looks really floaty.
I understand about the chain look, but when they start moving it should be fine.
Edit: Some new ideas for for ground damage for the next screen: