This achievement requires that you earn a combo of 30 in any game mode. Combos are awarded when you correctly complete 30 questions in a row. Speed does not matter. This most likely will only be possible in Training Room. Daily Tests are either too challenging or too short to reach a combo of 30. Training Room becomes available after you complete Daily Test for the first time. In Training Room, select Brain Training, Memory, and then Traveling. Choose easy difficulty. Now you just need to repeat the pattern that is drawn on-screen. Go as quickly as you can, but make sure not to make any mistakes. There is enough time to reach a combo of 35 or so.
*Glitch Warning* This achievement may not actually unlock for you in the game like many of the other achievements. When you meet the requirements, no achievement will pop on-screen. However, when you check the in-game achievement list, the achievement will be unlocked. If this happens, reinstall the game (NOTE: You will lose all your progress). Set your phone into airplane mode. Load up the game and complete the requirements for the achievement again. This achievement should unlock normally. Afterwards, disable airplane mode and the achievement SHOULD sync with your profile. Keep trying this method until it sticks to your profile.