The legend that started it all. This is a treasure to cherish.
You are Mario: plumber, pasta lover, and princess rescuer! (three 'p's)
Along with your bro Luigi, you jump, throw fire, and swim to Bowser's castle multiple times, only to find that Toad has been kidnapped and that Peach is in another castle. But once you find the last castle, then it's over before you know it.
There is no 'save' system, so it's one time through without failing kind of thing. The baddies are fairly easy to defeat, yet there are still some that require patience and timing to acurately knock out.
The levels are fun to run around on, but you can't make Mario backtrack to the start of the course. Once you begin walking, there's no turning back.
As for secrets, there are a few pipes to slide down and vines to climb up into the clouds above, collecting coins and green mushrooms. A simple game this is, yet to not be forgotten. Buy it for the GBA or the NES, just be sure to have it in your collection, preferably framed and mounted. (just kidding)