Pathfinding on real networks
Travle's map is political — countries and shared borders. Layover swaps in the network that actually moves people: scheduled flights. The day's challenge gives you constraints (regions to touch, budget, stops) and you assemble a working itinerary from real connections. The shortest path on an airline network is rarely the one geography suggests, which is exactly what makes it interesting.
Efficiency as the score
Borderline plays on the same map Travle does — real land borders. Every answer must share a border with the last one, no repeats — and when you trap yourself in a dead end, survival hangs on naming the closest unused country. The 'one hop deeper exists, find it' compulsion is the same.
When the route IS the puzzle
RailPass keeps the path-building format and swaps country borders for Europe's real train timetable: choose departures, make connections, and beat a deadline. RailQ inverts the format by hiding a real train route behind travel time, stop count, ridership, and operator clues. If Travle taught you to think in connections, both reward network reasoning.