A sequence flashes, you repeat it back, and it gets one step longer each time. Simple to explain, surprisingly hard to defend once you're at level eleven, sweating.

Sequence-recall games like this one are a near-direct test of working memory span — your brain's capacity to hold and accurately reproduce a string of information in short-term storage, a measure psychologists have studied since the 1950s using almost exactly this format (watch a sequence, repeat it back, see where it breaks). Most people's raw span tops out somewhere in the 7–9 item range without using tricks like chunking (grouping items into patterns rather than memorising them individually), which is roughly where most players here start to feel the wheels come off. It's not about being naturally gifted with sequences; it's almost entirely about whether you're chunking instinctively or trying to hold every single tile in memory individually.