Hello Wynn,
When you collect 5 consecutive gold blocks without stopping, you get a gold streak and a yellow square appears at the top bar indicating you make it. You need to continue collecting gold streaks until you chain 10 in a row. Achieving 10 gold streaks in a row is challenging and here you have some hints to make it - focus on this achievement at the start of the game, as it gets harder as you go deeper, and use some boost to get the first chains quicker.
Good luck!