Ha,ha what a coincidence! While you made this drawing the current and brand new Gatchaman spin-off Gatchaman: Crowds is still going on. Speaking of which ever thought of doing fan art for the modern spin-off?
Wonderful composition! I love it! I'm too young to have watched this show but I know my older brother did. It was called Battle of the Planet as well here (Well "Bataille des plančtes" as we live in a french-speaking area.