You're seeing that the test has an enormous psychological component. It's one thing to know how to solve a question. It's quite another to be sufficiently clear-headed for a good approach to occur to you under pressure. If you haven't tried it yet, I'd give mindfulness meditation a whirl to help address this: https://www.theatlantic.com/health/archi ... on/275564/One thing I have to admit is that I got so accustomed to casually answering the questions that I forgot the stress a ticking clock can induce. I remember saying to myself "gosh 2 mins in and I don know how to tackle this question what do I do what do I do" and that added more stress and well I probably not only got that wrong but I just forbade myself the luxury of time on other questions too! So I think that that too is part of what you call the game and like I said I ended all my exams literally just guessing the last 3-4 questions and also doing 2-3 before those under lots of pressure so Im sure that hurt my score a lot.
(Also, it's not a terrible idea to continually remind yourself that the questions on the GMAT are engineered precisely to appear more challenging than they are. In order to be a valid question, it has to be solvable in a short amount of time. Put another way, if you don't see a good approach right away, there's no need to panic, because once a good approach does occur to you, it's unlikely that the question will take more than 30-45 seconds to solve. So rather than rush, it's better to take a breath and methodically consider another strategy if your first one doesn't appear to be working.)