Classic Mode
Classic mode has two game types to choose from: trace a One-Stroke Puzzle in a single unbroken stroke, or explore a Maze Kingdom labyrinth — both with no timer, so you can take your time and think through the path before committing. One-Stroke Puzzle is rooted in the 18th-century Königsberg Bridge Problem and Euler's graph theory.
How Classic Mode works
Classic is TraceBlazer's no-pressure mode. In One-Stroke Puzzle, you're given a network of connected nodes and edges and have to trace every edge exactly once without lifting your finger or mouse — the same problem Leonhard Euler solved for Königsberg's seven bridges in 1736, which became the founding idea of graph theory. In Maze Kingdom, you navigate a fog-shrouded labyrinth from entrance to exit instead, at your own pace, with no clock running.
Each game type has 10 difficulty levels. Early levels have just a handful of nodes or a short maze corridor; by the later levels you're tracing dense, overlapping graphs or multi-room labyrinths where the shortest visible path usually isn't the one that lets you cover every edge or reach the exit.
Tip
Before you start tracing, look for nodes with an odd number of connecting edges — Euler's theorem says a path exists only if there are zero or exactly two such nodes, and if there are two, your path has to start at one of them and end at the other.