Click a numbered signal pin on the BGA. Lay Manhattan waypoints (same row or column as the previous point). Click the matching target on the edge to complete the trace. Drop a via to switch layers when you need to cross. Solve every route to pass the level.
score = max(0, base − length·5 − vias·50 + bonus·2)
Base 1000 per level. Trace length penalty (5 per cell) rewards short routes. Via penalty (50 per via) rewards single-layer solves. Time bonus (2 per second remaining vs target) rewards quick solves. Stars: 3 ≥ 85%, 2 ≥ 65%, 1 = pass.
BGA escape routing is the single highest-leverage decision on a real high-speed PCB. Pin pitch sets the stackup, the via type, the layer count, and the routing channels you have to thread. This puzzle is a simplified-but-honest model of the same constraints — see the BGA escape pillar for the real-world version.