This is a very in-depth star coins guide, this page linking specifically to World 1-6. http://www.gamespot.com/features/6239398/p-7.html
Because there are two "one-ups" and coins to be had! :)
You have to collect all 3 Koopa Coins in every level of that world.
No, but if you get all the Star Coins in a world, you unlock a level in world 9.
they r worth 10 coins and if u collect all of them in 1 level u get somthin
u watch video walkthrough!
how do you pass world 6 on level 6 on new super Mario bros
There are nine worlds in New Super Mario Bros. Wii. When you get all of the Star Coins in World One you unlock World Nine Level One and so on. World Nine is like Rainbow Road on Mario Kart.
yes
look up super Mario bros Cannon world 1 and level 1
yes and it is a city but to get it you have to get all the star coins in world 9 sorry if I am mixed up with[super mario galaxy]
no in new super Mario bros there is no level 0 there is only worlds like world 1,2,3,4,5,6,7,8
You collect them because after you beat World 8 there's a secret world, World 9, and to unlock the levels you needs all the star coins in a specific world (ex- to get level 1 in World 9 you need all the star coins in World 1)