Sudoku is a number puzzle. Sometimes Sudoku is called a magic square, which is generally not true, since Sudoku is a Latin square of the 9th order. Sudoku is actively published by newspapers and magazines in many countries of the world, Sudoku collections are published in large numbers. Solving Sudoku is a popular pastime.

Minesweeper is a logic puzzle video game genre generally played on personal computers. The game features a grid of clickable squares, with hidden “mines” scattered throughout the board. The objective is to clear the board without detonating any mines, with help from clues about the number of neighboring mines in each field.

Fifteen is a 15-game puzzle game in which 15 numbered square tiles can be moved around a 4×4 square board (one cell remains empty).

Tetris is a puzzle based on the use of geometric figures “tetramino” — a kind of polyominoes consisting of four squares.

Tic-tac-toe is a logical game between two opponents on a square field of 3 by 3 cells or larger (up to an “infinite field”). One of the players plays with “crosses”, the second — with “zeros”.