Hacking heist 'em up Quadrilateral Cowboy has won the Grand Prize at the 2017 Independent Games Festival awards, taking home $30,000 (and another $3,000 for winning the Excellence in Design award). The ceremony went down last at the Game Developers Conference, with other winners including Ladykiller in a Bind and Hyper Light Drifter. The IGFs may no longer turn up many huge surprises but they…