I was never clear on whether this needed to simply be 3 sets of special tiles, or if it was supposed to be one set of each of the 3 different types of special tiles. To be safe, go for this achievement in Dash mode, since this is the only place that you can get the Wild, Gem, and Time tiles. In a single game, get either any 3 sets of special tiles, or one of each type to unlock this achievement. If you can verify which of these two options is correct, please feel free to message me and I will update this and credit you for the clarification.