Every people have different thoughts. If you think trading is fun, then it goes to be a game for you. Seriously, some investors think that this is not a game or fun for them. They invest a lot of money, some of them fail to earn, but some of them earn a lot of money. Only you can decide if trading is a game or take it seriously.
For me it depends on how you deal and handle with it, trading is quite risky, it takes bravery and readiness to be part of it and specially time and energy for you to survive. Look for something that works best for you, we have a different strategies and action plans when we engage in trading. Call it a game, fun, or gambling, but don't forget to play with it wisely and seriously.