1. Someone who randomly or vigorously presses or 'bashes' buttons, especially those of video game controllers. See: button-bashing.
2. A video game where the gameplay descends into the mindless random, or repeated, pressing of a button or buttons. See: button-bashing.
3. A fighting (video) game, such as Virtua Fighter, Soulcalibur or Tekken, etc.
"I'm not playing Tekken with you because it's just a mindless button-basher. Plus, you're gay."