I think you did a wonderful job here. If I may, I'd like to suggest that you do some extra shading details. Just study how light casts shadows from nearest to furthest from the subject. right now the shading goes too far "down" when it should have some foreshortening. You can easily change that by how the shadow's side-lines extend out like a trapezoid instead of like a rectangle. It took a bit for me to get that, so I'm just passing it on. Also, you can make the shading under each person a little darker to give a more realistic feel. The more you learn about shading, the more you realize there's shadows within shadows. xD But you don't have to go too far out there in anime/manga. I grew up with this You're done eally well with balance and proportion, which is what caught my eye. Just one rule with people: 2 head widths = 1 chest. You can balance out a body based on head lengths. I've found it kinda funny. ^^
I think my fav part about this is your sun rays and your coloring. You also have a good eye for detail too.