AURA looks like an inventive take on the traditional "twin stick" shooter experience, focused primarily on exploration. It seems really interesting sonic experiences are involved too—the fuel you gather for your tiny flying ship is linked to musical "nodes", and you assemble a song as you go.
I've actually not played it; I think it requires a traditional controller be connected to your computer (update: turns out you can use a mouse and keyboard input, too). I wanted to show it to you, though, because I think the trailer is absolutely lovely and musical, and because it's easy to recommend the work of UC Santa Cruz's Games and Playable Media Masters students: AURA was made by Patrick Trinh and Lun Cao for that wonderful and reputable game design program.
$5 will buy you the chance to experience it for yourself.