This journey began on February 19th, 2004 and takes place in Pokemon Blue. No gamesharking has been done to improve the stats of the Puffs or the Cinnabar item-multiplying trick to make the game easier. Just good old-fashioned training by the game's natural state.
I chose the game Blue because in the beginning intro it shows a Jigglypuff fighting against a Snorlax, and despite major differences in size and weight, the Jigglypuff takes the initiative and attacks Snorlax. And having my Puffs fight against the game's two sleeping giants, I have no doubt that brave Puff from the intro gave that Snorlax hell. =P
As far as the battling goes, only the Puffs are kicking butts; Dux the Farfetch'd is only used to Cut trees & Fly to different places while Fonze the Squirtle is only used to Surf. It's just as well; these puffs can take care of themselves.
Surprisingly enough, Jigglypuffs are pretty strong and handle well in battle. While there are some problems we have to deal with (like going against Fighting, Rock, and Ghost types); the attacks they naturally learn are usually effective. My favorite moves are Sing & Body Slam; Sing, obviously, because opponents can't fight if they're snoozing and it makes them easy targets (not to mention it's Jigglypuff's trademark), and Body Slam because it's strong, has a high accuracy rate, and can paralyze. Very sweet indeed.
Another nice thing about Jigglypuffs is that they can learn a wide variety of TMs, which comes in handy when physical attacks like Body Slam do little-to-no damage. Some of the great special attacks they can learn include Watergun, Ice Beam, Thunderbolt, and Psychic. Learning these excellent TMs is a great way to overcome some of the types they have problems with, like Ghost, Rock, and Fighting.
As for how the journey has been so far, the Puffs are fighting quite well. When I first started, I depended heavily on them using Sing since Pound didn't do a lot of damage and their Defense stats were low. But as they grew and learned stronger attacks, I found myself depending on Sing less and less, as their strong attacks and high Attack stats usually KOed the opponents in one-to-three turns. Even now, half way through the game, I usually only have them use Sing if the opponent is at a much higher level than the Puffs or is using devastatingly strong attacks.
As of March 14th, sometime before noon, the Puffs have defeated the Elite Four & Champion rival. In whole, I've logged 38 hours and 47 minutes into the game. And so it is my pleasure to proudly say that you CAN beat the game using a team of Jigglypuffs, with training and strategy. How embarrassing for the Elite 4, losing to a bunch of Puffs... XD