About the 50x50 preset
This is a starting point for the custom game builder: a massive 50×50 board carrying 450 mines across 2500 cells, or 18.0% density. That puts it in the same difficulty band as Intermediate (40 mines on 16×16), so what changes here is scale rather than difficulty — 2050 cells to clear instead of 216.
Tips for This Size
Large grids require patience and methodical clearing. Start from multiple points.