How the daily set works
Difficulty climbs across the week: gentle grids to open it on Monday, medium ones in midweek, hard ones to close out the working week, and every game's top level for the weekend.
Your streak grows by one for every calendar day on which you finish at least one daily puzzle. Miss a day and it starts again from zero; your best streak stays on record. Streaks live in this browser only, so a different device keeps its own count.
Unfinished daily puzzles are saved like any other game. You can switch between the five tabs and come back to each one later the same day.