The Boston Film Festival kicked off Thursday night with a screening of “Head Games,” a documentary by Steve James about former wrestler Chris Nowinski’s investigation into head injuries and sports. VIPs who walked the red carpet before the screening included James (who also made “Hoop Dreams”); producer Steve Devick; former NFL player and Harvard grad Isaiah Kacyvenski; and the film’s star, Nowinski, who also went to Harvard. The Boston Film Festival runs through Monday at the Revere Hotel’s Theatre.