Lady Gaga’s role in the Joker sequel has been blasted by fans who’ve moaned she barely features, RadarOnline.com can reveal. The singer, 38, stars alongside Joaquin Phoenix in the blockbuster, playing Harley Quinn, which is part musical. Gaga fans have been left disappointed after watching Joker: Folie à Deux due to her minimal involvement, as she’s only on screen for 33 minutes, which is less than a quarter of the entire movie. One Gaga fan ranted: “I spent $150 on a night out to see the movie because I’m a massive fan – and she was barely in the thing. You’re better off just watching the tra…