Good Egg Galaxy

The Good Egg Galaxy is the second galaxy Mario must venture to in Super Mario Galaxy. It is the first galaxy within the Terrace dome. It is a galaxy which, unlike many of the others in the game, does not have a set theme such as ice or fire. Rather, it mainly consists of multiple small planetoids and a variety of different themes that usually contradict each other. Because of this, it is arguably the most 'true' galaxy with a pure space theme. The galaxy starts on a planet with a garden and a house on top and a castle at the bottom. Dino Piranha and King Kaliente are fought in this galaxy.

Starting Planet
The Starter Planet has two sides. One is green with a house on it and two groups of flowers where the player can get Star Bits. The other side is dark and has a tower on it. It also has dry trees. On the tower side the player can get lots of Star Bits.

Pill Planet
The Pill Planet is shaped like a giant, transparent pill. It contains many obstacles and items, mainly Coins and Item Crystals. Atop the towering planet is a Launch Star that Mario can use to break out of the Pill Planet's glassy surface. This planet contains a 2D platforming area with variable gravity.

Magma Planet
This is where the boss battle against King Kaliente takes place. It consists of a hot lava pool with a shiny tar-like ring of ground around it. The rest of the planet is just simple hot rock. The planet is quite big compared to others like the Tropic Planet, since it needs to have a decently large size for the fight to be held. Underneath the Magma Planet is a rocky area with yellow rings on it like a target.

Egg Planet
One planet resembles a Yoshi Egg. This planet can be found in the mission known as A Snack of Cosmic Proportions, where a hungry Luma will await a feeding. There is also a green planet and a red planet which are part of a circle of launch stars with the Yoshi Egg Planet in A Snack of Cosmic Proportions

Geo Planet
The Geo Planet is a small planet where the Dino Piranha boss is battled. it is made of gravel and rock with hints of grass sticking out, much like a simple ball of earth mixed up together. There are Item Crystals on it with a few Coins in them.

Boulder Planet
It is a yellow planet that resembles a peanut with little grooves where the boulders have been rolling. It has about 6 boulders that Mario must dodge and/or break. It had a different color appearance when it was first seen, but it ended up appearing with a recolor in the final version of the game. It was originally blue.

Star Planet
The last planet of the second star, Which resembles a Sling Star. To get to the star, the player must use Pull Stars to get to the Power Star in the centre.

Tower Planet
This planet requires jumping up cliffs to reach the top. It is full of Spiny and Round Bushes and only appears after the Hungry Luma is fed 100 Star Bits.

Flip Switch Planet
A planet covered in flip switches. Complete the challenge for a 1-Up mushroom. It is a secret planet that can only be accesed by defeating a Piranha Plant in the Bitten Apple Planet.

Bitten Apple Planet
A planet that, as its name tells, looks like a green bitten apple. There are Boulders rolling all over the planet and a purple Piranha Plant on the top. There is a black hole inside it. In the Speed Run of the level, Boulders are replaced by Chomp Heads.

Enemies

 * Goombas
 * Electrogoombas
 * Swoopin' Poinks
 * Pokeys
 * Boulders
 * Piranha Plants
 * Moneybags
 * Chomps
 * Bullet Bills

Dino Piranha
Mario starts this level on a planet with a grassy scene and a house on one side and a dark tower on the other side. At the top of the tower is a Sling Star which propels Mario into a Launch Star. This sends him to the Boulder Planet, where five Star Chips are scattered. The player will have to dodge the boulders and collect the Star Chips to create a Launch Star. Mario lands on a small planet with a Piranha Plant. Mario must defeat the plant to make a sproutle grow. Mario must Star Spin up it. Next Mario must climb the stones on the next planet to the Launch Star. Mario will launch and slam into a giant egg, which will begin to move around. After Mario does a Star Spin on the ball on the end of it's tail, it will hit the egg and break it, revealing Dino Piranha. It must be defeated to get the star.

A Snack of Cosmic Proportions
This level involves feeding a Hungry Luma one hundred Star Bits, so the player should pick up as many as possible. When Mario is exploring this planet, he must hop up the stone stairs on the tower side of the planet and he should talk to the blue Luma. It'll transform into Pull Stars which lead to a Launch Star. This leads Mario to a set of three planets connected by Launch Stars. The planet that resembles a Yoshi Egg is the one that has the the hungry Luma. Mario can use the Launch Stars to travel around the three planets as much as he wants to fulfill the Luma's quota of Star Bits. The player must talk to the hungry Luma after getting 100 Star Bits, and it'll explode with snacky happiness and create a new planet and Launch Star. The player must climb up the structure on this new planet to reach the Launch Star at the top, which will launch Mario to the Pill Planet. One of the crystals on this planet covers the entrance, so the player must smash it to get inside. The player will enter a 2D platforming area, so Mario must head through it carefully. The top of the planet contains a Launch Star. Mario will finally end up on a star-shaped structure with blue Star Chips and the Power Star in the middle. The player has to collect the blue Star Chips to create Pull Stars, which will aid Mario in grabbing the Power Star. The player could also use a long jump to get the star without collecting the blue star chips.

King Kaliente's Battle Fleet
Mario starts on the same planet as he did on the previous two missions. The Launch Star is on the top of the house, and it is possible for the player to triple jump to the top of it, or else Mario can take the orange Warp Pipe on the underside of the planet and traverse the boxy room to reach the Launch Star. The Toad on this planet tells Mario that the spiky plants hate coconuts. Mario will have to kick the coconuts into the plants, and one will reveal a Sling Star. The next planet has a large Pokey, which can also be defeated by kicking a coconut at it, revealing a Launch Star. The next planet has a Sling Star which propels Mario to a planet full of electrical walls, but if the player decides to stay on the planet they can enter a pipe to an area with a Rainbow Star and lots of Goombas. The player must carefully avoid the walls of the next planet to reach the other side of the planet, where cannons shoot Bullet Bills. The Launch Star is in a crystal at the top of the structure on this planet. As Mario is launched onto a airship, two creatures will shoot coconuts at Mario from an adjacent airship. Mario will have to do a Star Spin to send the coconuts back at them to defeat them, which lowers the bridge between the two ships. The Launch Star on this airship that takes Mario to King Kaliente's planet. The player can defeat King Kaliente by repeatedly spinning back the coconuts he shoots at Mario.

Dino Piranha Speed Run (Speedy Comet)
Identical to 'Dino Piranha', but with a time limit of 4 minutes.

Purple Coin Omelet (Purple Comet)
In this level, the player has to collect 100 purple coins to get the Power Star. Mario must traverse through the galaxy and collect these coins using launch stars. Unlike most other Purple Comet missions (with the exception of Purple Coins in the Woods), the coins here follow a linear path - simply follow the trail of coins on the first planet, take the Launch Star, take the Launch Star in midair on the way, follow the path of coins on the second planet, etc. If the player repeats this process a few times, they will have collected every coin and will land right next to the Power Star.

Luigi on the Roof
Shortly after Mario rescues his brother Luigi in the first mission of the Ghostly Galaxy, Mailtoad will inform Mario that Luigi has sent him a letter saying he is lost, with an enclosed picture of his whereabouts. The player can work out that Luigi is in the Good Egg Galaxy. To clear this hidden Star mission, the player must enter the mission Dino Piranha (after receiving the aforementioned letter) and reach the top of the mushroom hut on the first planet. The easiest method of reaching the top is simply doing a Triple Jump and Star Spin on top of it, but another way is to walk around to the underside of the planet and enter the orange Warp Pipe there. After traversing the room, possibly gaining a 1-up from collecting Music Notes, the player can jump through another orange Pipe and emerge on the top of the Hut. Luigi will give Mario the Star and the mission will be completed.

Trivia

 * Unlike most galaxies, it gets its name from a single planet.
 * It is notable that the original E3 demo and gameplay footage mostly featured segments from the Good Egg Galaxy, along with a mixed-in level from the Space Junk Galaxy.