“…Amongst other games to have been proved NP-complete or harder are the card solitaire games Klondike (Longpré & McKenzie, 2009), Freecell (Helmert, 2003) and Black Hole (Gent, Jefferson, Kelsey, Lynce, Miguel, Nightingale, Smith, & Tarim, 2007), the Sudoku puzzle (Takayuki & Takahiro, 2003), video games like Pac-Man (Viglietta, 2014), and casual games such as Minesweeper (Kaye, 2000), Candy Crush Saga and Bejeweled (Walsh, 2014;Guala, Leucci, & Natale, 2014). Many other games are surveyed by Kendall, Parkes, and Spoerer (2008) and by Demaine and Hearn (2009). In each case, the complexitytheorist must define a generalised class of instances.…”