Nineline

NINELINE is a Game Boy one-line puzzle game where every move matters. Draw a single continuous path that starts at 1, passes 1 through 9 in order, fills the entire board, and never crosses itself or a wall. With 500 uniquely solvable levels, a relaxed Adventure mode, and a higher-stakes Challenge mode, it’s a clean, brainy puzzle experience built for quick sessions and deep mastery.