The thief himself barely matters in Thief Puzzle; what you control is his hand. Each level shows something valuable sitting somewhere in the scene, and you guide that hand toward it, threading it around obstacles and past whatever security has been set up to stop you.
The levels are small 2D puzzles. Understanding the goal takes a second, while actually reaching the prize takes thought, because a careless route runs straight into trouble. Every successful heist is followed by a trickier one, so the puzzles keep growing and ask for more creative answers. The tone stays lighthearted, with plenty of humor in how the situations are set up.
Before moving, it pays to study the whole scene and spot every hazard, since the right solution is often a less obvious path. For a number puzzle with no burglary involved, there is Sudoku Classic.