Very well done. There's not alot of fanart featuring the girls in their Riders outfits although I liked those. Cream's little visor is just too cute. I love the background too and the shading is nice, gives it an almost tropical feel. Little Cheese looks nice as well.
This is a very nice piece, and seems very summertime-ish. I like how you have Amy & Cream in their sporty "Riders" outfits, I always liked those outfits, and I like the coloring, and the shadow looks great. I also like the lineless style, and stylish background to. Very good work on this.