What is the point of the Bongcloud Opening anyway? Should be renamed Bongohead Opening...
Bongcloud Nomenclature

I have beaten people over 1800 with the Bongcloud. I have had a few good games against 2000+ opposition.
Anyways I prepared for that in my theory. I have variations if white plays a pawn move.

Out of all of those, only 5 were true Bongclouds. Most of those games were Hammerschlags. Even then, the few that were Bongclouds had the king move right back the next move which is a sign of weakness. It does delight me though that another player plays oddball openings. Nice find.

Here is another updated list of variations.
1.e4 e5 2.Ke2 Nf6 3.d3 d5 4.f3-Fortress Variation
1.e4 e5 2.Ke2 Nf6 3.Qe1 Nxe4 4.Kd1-Bongcloud Gambit
1.e4 e5 2.Ke2 Nf6 3.Kf3-Outflank Variation
1.e4 e5 2.Ke2 Nf6 3.Ke3-Kamikaze Variation
1.e4 e5 2.Ke2 Nf6 3.Kd3-Bongcloud Zigzag Attack.
1.e4 e5 2.Ke2 Nf6 3.Ke1-Boncloud: Bongcoward/Light-Weight/Yellow Variation
1.e4 e4 2.Ke2 Ne7-Bongcloud: Alapin Variation
1.e4 e5 2.Ke2 Nf6 3.Ke1 Nxe4 4.Ke2 Bongcloud Piano
1.e4 e5 2.Qh5 Ke7-Parham Attack: Bongwater Blunder
1.e4 c5 2.Ke2-King David Attack
1.e4 c5 2.Nf3 Qa5 3.d4 Kd8-Sicilian: Magic Dragon
1.e4 c6 2.Ke2-Caro-Kann Defense: Mad Hatter's Attack
1.e4 c6 2.Ke2 d5 3.Ke1-Caro-Kann Defense: Puff-Puff Gambit
1.e4 f5 2.Ke2-Fred Defense: Bongcloud Chocolate Gambit
1.e4 e6 2.Ke2-French: Bongcloud Napoleon Attack
1.e4 e6 2.Ke2 e5 3.Ke3 Ke7 Old Steinitz Bongcloud
1.e4 e6 2.Ke2 Nf6 3.Ke3 Bc5 Bogo-Bongcloud
1.e4 d6 2.Nf3 Nc6 3.Ke2 Delayed Bongcloud
1.e4 d5 2.Ke2-Scandinavian Defense: Cheese Danish Attack
1.e4 d5 2.Ke2 Kd7-Scandinavian Defense: Raspberry Danish Counterattack
1.e4 Nf6 2.Ke2 Alekhine's Defense: Bongcloud 420 Variation
1.e4 Nc6 2.Ke2-Nimzowitsch Defense: Bongcloud Variation
1.e4 g5 2.Ke2-Borg Defense: Bongcloud Stoned Game
1.e4 g6 2.Ke2-Modern Defense: Purple Haze Variation
1.e4 b5 2.Ke2-Portuguese Defense: Flying Trout Attack
1.e4 b6 2.Ke2-Owen's Defense: Bongcloud Singing Owls Variation
1.e4 d6 2.Ke2-Pirc Defense: Bongcloud Variation
1.e3 e5 2.Ke2 d6 3.Kd3 d5-Ricecake9 Burrito Attack
1.f4 d5 2.Kf2-Bird: Bongcloud Flying Kite Variation
1.f3 e5 2.Kf2 d5 3.d3 Nf6 4.b3 Nc6 5.h3-Reefer Formation
1.g3 e5 2.e3 d5 3.Ke2 c5 4.c3 f5 5.a3-Munchies System
1.g3 e5 2.e3 d5 3.Ke2-Benko Opening: Indian Bongcloud
1.c4 c5 2.Qa4 Nc6 3.Kd1-English: Pseudo-Bongcloud
1.d3 e5 2.Kd2-Bongcloud: Dragon King Complex
1.d3 e5 2.Kd2 Nf6 3.g3-Dragon King of the North: Ao Shun
1.d3 e5 2.Kd2 Nf6 3.b3-Dragon King of the South: Ao Qin
1.d3 e5 2.Kd2 Nf6 3.Nc3-Dragon King of the East: Ao Guang
1.d3 e5 2.Kd2 Nf6 3.Nf3-Dragon King of the West: Ao Run
1.d4 d5 2.Bg5 Kd7-Bongcloud: Anti-Rich Counter
1.d4 Nf6 2.c4 e6 3.Nc3 Ke7-Bongcloud Indian Defence
1.d4 Nf6 2.Kd2-Peace Pipe Cloud
1.d4 d5 2.c4 c6 3.Nf3 e6 4.Nc3 Kd7 5.e3 Kd6-Semi-Slav: Burnt Pizza Counterattack
There is room for more names if I missed any. In addition you can lay claim to your own variation if it has not already been claimed.

I'm curious, having just started a Bongcloud game myself - is the rule that you just have to play Ke2 and then continue the game as normal, or do you have to continue to try and advance the king to your opponent's back rank? Is it considered bad form if you return the king to his home shortly after? Has anyone codified the rules regarding Bongcloud play?
Yep...returning home is legit. It's one of the most clever variations, imo. Some call it the "Homer." Mmmmm home.
Part of the Bongcloud's effectivness may be psychological. Observe the face of your opponent when they first see Ke2....priceless.
Not the dreaded Simpson defence?

1.e4 f5 2.Ke2 Kf7-Fred Randel Counter
1.d4 f5 2.Kd2-Dutch: Apple Pie Attack
1.d4 f5 2.Kd2 Kf7-Dutch: Apple Cobbler Counterattack

To Conquistador: I noticed that you were missing a name for the (1.e4 Nc6 2.Ke2) variation of the Bongcloud opening. Well it now has a name "The Bongcloud-Bogart" variation. And here is what you may find yourself in if black decides to develop both his Knights in his first 2 moves! But first, it is critical that you take note of some key concepts to playing the Bongcloud-Bogart. Firstly, the Queen is not all that important in this variation and you shouldn't hesitate in letting her go for the sake of gaining tempo. The key here is getting your king to the center of the board asap, and then developing your queenside pawns into a "Pawn-Fort" in the center where your King can hold out as a "gate-keeper" until we can muster a second drive deep into black's rear. Focus on a pawn-fort (minimum 3 pawns) that points towards a7, this is where we want to focus our attack, by flanking, and letting our king control the d-file. Finally, use any left-over minor pieces to keep that f5 square vacant! (for reasons that will be evident) And for Pete's sake!... Protect that h2 pawn! The last thing we need is black flanking you! You must also remember to ALWAYS promote your pawns to knights to confound black's gameplan. This variation is not for the novice...
So, to summarize: (1) Blitz your king to the center while developing your queenside pawns. (2) Use your minor pieces as fodder to developing your pawn-fort and let your king act as the gate-keeper to the d-file. (3)With your pawn-fort developed, use left-over minor pieces to keep f5 vacant, and protect h2. (4) Flank black by attacking a7. (5) Let your queen be captured to gain tempo, especially early in the game where getting your king out is so critical! (5) And finally, mess with your opponent's mind by always promoting to knights!
Mushroom City is an idea, but I cannot decide on a variation for it.