VS. Super Mario Bros. is a two-player VS. System version of Super Mario Bros. which was released in 1986. The original version of Super Mario Bros. has some levels repeat, with an easier version with some obstacles removed (Fire-Bars in the castle, fewer enemies, etc) earlier on, and then a later "full" version, e.g. 1-3 is the easier version of 5-3; 1-4 is the easier version of 6-4; 2-2/2-3 are the easier version(s) of 7-2/7-3; and 2-4 is the easier version of 5-4. In the arcade version, most of the "easier versions" (all except 1-3) are replaced by the "harder version" to make way for new levels. The following table summarizes the changes. Unlisted levels are mostly the same as the corresponding level in Super Mario Bros., but with minor difficulty increases. Various ?s, especially those that contain power-ups, are often either moved to much harder-to-reach places, or even removed altogether, or the power-ups are replaced with coins. Many bottomless pits and more enemies have been added as well.