World 8 (New Super Mario Bros.)

World 8 is the final world of New Super Mario Bros. Mario and Luigi traveled to this world in New Super Mario Bros. after defeating Monty Tank and/or Lakithunder, or using the W8 cannon in World 5. The boss of this world is Dry Bowser. He acts like regular Bowser, but he also throws bones. This makes it hard to jump over him. There is also a very simple way to defeat him, as Super/Fire/etc. Mario can simply run through him and trigger the Skull Switch. Then, after Mario or Luigi defeat him, a new bridge appears outside, and they head into a volcano.

After traversing through four more levels, they reach the second tower, filled with serpentine platforms. Finally, they reach Bowser's Castle, separated by other castles by its size and green color. At the boss fight, there is a brief animation of Bowser Jr. laughing, then putting Dry Bowser's remains into a cauldron (which resembles a cross between a scarecrow and a clown car). A larger-than-life Bowser exits. Bowser and Bowser Jr. turn around and look at Mario, and start the final boss fight (an unfair 2 vs 1 battle). After that, Peach is freed and gives him a kiss, and the credits begin to roll.

8-1 (Spooky Wasteland)
The first level in World 8 takes place on a barren wasteland, filled with Crowbers, and also has Bullet Bills, Banzai Bills, Boos and Splunkins. The first star coin is accessed by putting a spring on top of two blocks quite near the start. Mario will bounce up to the coin and drop down near the blocks. The next star coin is after the midway point, near a Boo. Mario has to jump on top of on top a Bullet Bill to reach the coin. The final coin is very close to the second, and directly underneath the path of a Banzai Bill. Mario must wait for the Banzai Bill to go over him, then jump down and get the coin.

8-2 (Skeeter-guarded Switches)
The next level is an underground level, with ? Switches that causes water to rise inside. The only enemies in this level are Skeeters. There is also a pipe which can be gone down if Mario is in his mini form. After one area, Mario goes to an area with many sinking barrels and Skeeters inbetween them. After getting past the barrel area, Mario can either go down the mini pipe or a normal one. The normal pipe leads to an area filled with Brick Blocks, which he can ground pound to get the first coin.

8-Tower (Bowser Jr's Fortress 9)
This is the second last Tower of the game. It features moving walls and spikes. Once the player gets to the top, they fight Bowser Jr.. During this battle he throws shells. It features moving walls and Rocket Engines as the obstacles.

8-3 (Unagis in the Cave)
This is an underwater level with many Unagis on a vertical stretch of the level near the start, before a horizontal area with a Mega Unagi which chases Mario/Luigi through the area. All of the Star Coins are in the horizontal area. Interestingly, probably because the level isn't at all peaceful, the underground music plays instead of the underwater theme. The level's background also looks like the underground background.

8-4 (Scuttle Bug's Web)
This level is filled with Scuttle Bugs and has a lot of moving platfroms. The first Star Coin is just before the midway point, on a high ledge. After going on some moving platforms, there is the second Star Coin, then an invincibility star. Mini Mario can access the third Star Coin, by going into a tiny pipe, with Micro Goombas in it. Also, there are several invincibility stars, helping Mini Mario to perform the jumps required to get the coin and get out. Then there is the flagpole

8-Castle (Dry Bowser's Castle)
This level is the second last Castle of the game. It features lifts which appear by hitting a block that's the same as in the Tower of World 2. The level is hard. The Boss of this castle is Dry Bowser. The fight is the same as Bowser's fight except that theres no lava below and it has no raising platform. After this Battle Bowser Jr. will run off with Princess Peach and a bridge will appear on the lava, leading to the second half of the World and he'll run off to another Tower.

8-5 (Koopa Volcano Outskirts)
This takes place around a volcano. There is a lot of lava, as well as unstable platforms. Podoboos come out of the lava, and generic enemies (such as Goombas and Koopas) also exist.

8-6 (The Horizontal-Wrap Volcano)
Takes place in a Volcano. Like the Tower in World 4, the lava rises. At the Goal you can Spin Jump off a Spin Block get extra points.

8-7 (Bros. Rest Stop)
A level that features every type of Bro. except, strangely, the Hammer Bro. It is the only level to feature both Fire Bros. and Sledge Bros. It also features many Paratroopas to be bounced off of.

8-8 (Meteoric Mania)
This level features a new species of Bob-Omb called a Kab-omb as well as Raining Debris. Raining Debris destroy blocks like Super Thwomps and appear from the erupting volcanoes in the background. The Player must run to the goal avoiding Kab-Ombs and Raining Debris. The level features music from World 8-5 and 8-6.

8-Tower 2 (Bowser Jr's Final Fortress)
This tower is very difficult. There is a moving platform in this level and Mario must stay on it. There are also spiked balls here. This is super difficult.

World 8 (Bowser's Castle)
The final level of New Super Mario Bros., being Bowser's Castle. The Mario Bros, once inside, will encounter a massive amount of traps, including Rocket Engines and Thwomps. The level is the longest in the game, and some parts of it require pressing one of the many ? Switches to be found. These switches will flip the gravity of the castle upside down, and any enemy along with it. This action is required for getting to certain doors.

The second part of the castle is a long looping room, similar to the looping castles of 4-4 and 7-4 from Super Mario Bros., which can be passed by walking on the right platforms, which players can tell because there is a buzzer noise if he/she passes along the wrong platform. After that is the boss door.

Once inside the room, the player will encounter Bowser Jr. on a long bridge over a deep pit. He will toss his father's bones into the cauldron, thus reviving him, much to Peach's horror.

The duo will then fight Mario together, with Bowser Jr. using his usual shell-tossing tactic, and his father breathing flames behind him. After the player defeats Bowser Jr., his father will increase his attacks greatly. Mario must then run under one of Bowser's giant jumps and hit the Skull Switch at the end of the bridge, ending the fight and winning the game. Another way to win is if the player has a Mega Mushroom as a stored item, jump on Bowser, then make Bowser Jr. fall after hitting the Skull Switch. The player can also hit the Skull Switch without defeating Bowser Jr., causing both him and Bowser to plummet.

Enemies Introduced

 * Kab-omb
 * Sledge Bro.
 * Fire Bros.
 * Crowber

Trivia

 * The racecourse Grumble Volcano from Mario Kart Wii slightly resembles World 8.