World 3 is an ice world while World 4 is a water world in New Super Mario Bros Wii. In New Super Mario Bros U, why is World 3 the water world
![Mario & Luigi: Bowser's Inside Story New Super Mario Bros. Wii Super Mario World New Super Mario Bros. U, castle princess, game, heroes png | PNGEgg Mario & Luigi: Bowser's Inside Story New Super Mario Bros. Wii Super Mario World New Super Mario Bros. U, castle princess, game, heroes png | PNGEgg](https://e7.pngegg.com/pngimages/754/738/png-clipart-mario-luigi-bowser-s-inside-story-new-super-mario-bros-wii-super-mario-world-new-super-mario-bros-u-castle-princess-game-heroes.png)
Mario & Luigi: Bowser's Inside Story New Super Mario Bros. Wii Super Mario World New Super Mario Bros. U, castle princess, game, heroes png | PNGEgg
![New Super Mario Bros Wii - Co-Op - Part 5 World 3-4, 3-5, 3-Boss | Super mario bros, Super mario, Mario bros New Super Mario Bros Wii - Co-Op - Part 5 World 3-4, 3-5, 3-Boss | Super mario bros, Super mario, Mario bros](https://i.pinimg.com/originals/a0/f0/1f/a0f01f6655de05f41159c0fbcb78f9df.jpg)