Short answers, pulled from the story.
Colombia lost the hosting rights because President Belisario Betancur declared on the 5th of November 1982 that they could not afford to host under FIFA's terms. A special FIFA committee announced on the 31st of March 1983 it would only consider Mexico's bid after claiming the United States and Canada had deviated from criteria.
Eleven cities hosted the tournament with a total of twelve stadia used including Mexico City, Monterrey, Toluca, Guadalajara, León, Irapuato, Querétaro, Nezahualcoyotl, Puebla, Zapopan, San Nicolas de los Garza, and the Estadio Tecnologico in Monterrey. All stadia except Monterrey were located in central Mexico while Group F played exclusively in the northern city of Monterrey.
Diego Maradona received the Golden Ball award as the best player of the tournament for scoring five goals and creating another five for his teammates. He scored two famous goals against England in the quarter-final known as the Hand of God goal and the Goal of the Century.
The official mascot of the 1986 FIFA World Cup was Pique, a jalapeño pepper with a moustache and Colimote sombrero. Its name comes from picante, a Spanish word meaning spicy, and was also a pun on the PK abbreviation of penalty kick.
Twenty-four teams qualified for the final tournament including representatives from AFC, CAF, CONCACAF, CONMEBOL and UEFA regions. Three teams qualified for the World Cup for the first time: Canada, Denmark and Iraq.