"Games don't forgive bugs — a wrong score, a frozen timer, or a crashed leaderboard kills the experience instantly. I tested every layer of this multiplayer quiz game: real-time sync between players, scoring logic under rapid fire answers, countdown timer accuracy, streak bonuses, in-app purchases, and leaderboard integrity across both web and mobile. Found and documented 19 bugs including a critical race condition that caused two players to simultaneously receive winner status. Every edge case, every device, every scenario — covered."