I should preface this story by telling you that for as long as we can remember, Colin has always done this thing with his feet when he gets excited. We notice him doing this when he is watching Mickey Mouse and most especially, some kind of sporting event on TV (preferably basketball!). As he gets excited, he flexes his feet and straightens out his legs. It's hard to explain (but you will see it in the video).
This weekend when my family was playing Wii bowling, Colin was getting excited as he watched all of us take our turns (especially Daddy). This video captures Colin's "excited feet" pretty well as wii bowl!