Fig. 1: The BLS game.

In a, we present the BLS gameplay. Players are tasked with aligning the colored bricks, representing nucleobases, to the guides on the left, by inserting yellow gap bricks. They receive a bonus for full rows and must reach the par score to progress to the next puzzle. In b, we show the BLS pipeline from data collection to alignment output, in particular how data flow from the initial alignment of 1 million sequences to the analysis results featured in this paper. The Supplementary Information provides details pertaining to each step, regarding game design, puzzle generation, filtering and realignment.