A little something I found while playing Super Mario Bros. 1

[Suber Bloober]

Take World 3-1 for example. Get to the checkpoint, then wait by the pipe. Make sure at least one of the hammer bros. are on the screen. If you wait long enough, the hammer bro. will start to follow you. Nothing big I found. Just something to try.


******SPOILER******

[Deezer]

That's something I always thought was cool. They start to pursue you after about 110 game seconds. Source: http://themushroomkingdom.net/smb_breakdown.shtml#bad ;)