began using a mouse to play puzzle games. Modern puzzle games In 2001, PopCap Games released Bejewled, a direct clone of the 1994 tile-matching game Shariki with improved visuals. It sparked interest in the match-three mechanic which became the foundation for other popular games, including Candy Crush Saga and Puzzle & Dragons, both from 2012. Portal (2007) was followed by other physics-based puzzle games. Subgenres Physics game A physics game is a type of logical puzzle video game wherein the player must use the game's physics and environment to complete each puzzle. Physics games use consistent physics to make games more challenging. The genre is popular in online flash games and mobile games. Educators have used these games to demonstrate principles of physics. Physics-based logic puzzle games include Portal, The Talos Principle, The Witness, Braid, Fez, World of Goo, and Cut the Rope, and projectile collision games such as Angry Birds, Peggle, Monster Strike, and Crush the Castle. Coding Coding games are logical puzzle games that require programming elements. Examples include The Incredible Machine, SpaceChem, and Infinifactory. Exploration This subgenre includes point-and-click games that often exhibit similarities with adventure games and walking simulators. Unlike logical puzzle games, these games generally require inductive reasoning to solve. The defining trait is that the player must experiment with mechanisms in each level before they can solve them. Puzzle elements often do not have consistency throughout the game, and thus require guessing and checking, and exploration to reveal more of the puzzle. Exploration games include Myst, Limbo, The Dig, Monument Valley, and escape room games such as The Room. Sokoban Hidden object game A hidden object game, sometimes called hidden picture or hidden object puzzle adventure (HOPA), is a genre of puzzle video game in which the player must find items from a list that are hidden within a scene. Hidden object games are a popular trend in casual gaming. Tile-matching In tile-matching video games, the player manipulates tiles in order to make them disappear according to a matching criterion. The genre began with 1985's Chain Shot! and has similarities to falling-block games such as Tetris. This genre includes games that require pieces to be swapped such as Bejeweled or Candy Crush Saga, games that adapt the classic tile-based game Mahjong such as Mahjong Trails, and games in which pieces are shot on the board such as Zuma. Puzzle games based on Tetris include