the falling things look more like leaves than his feathers

Poor Icarus. Anywho, something about how the figure is drawn makes me want the lines to be a bit more natural. Maybe it's the hands, they're a little dead looking. Nice idea though!

To make the fall look less intentional, I'd suggest some asymmetry. For a quick edit, just move one arm up beside its respective hip, and flip the other arm so it bends the other way (with the thumb on the other side too). For something a little more intesive, a completely different falling posture might be desirable, perhaps back-first with all the limbs wind-swept up, feathers curling around. You're the artist though, I am sure you can carry this idea through.