World 1 got mushroom and peach castle
Levels
World 1-1
This level is very basic, with the background giving a view of Peach's Castle. There are basic enemies such as goombas and koopas, and some rotating hills. The Propellor Mushroom is introduced here.
New Super Mario Bros Wii - Co-Op - Part 1 World 1
First star coin in 1-1
Star Coins
#1 Just after the checkpoint, you'll find the first coin hovering above a trio of item boxes. To grab it, grab the Propeller Suit from the item box below (or the one just beyond) and use it to spin into the coin. If playing multiplayer, you can also jump off a teammate's head.
#2 After the checkpoint, stop at the third spinning-ground section (also the 5th one in the level) and wait for an opening to reveal itself, allowing access to a warp pipe (you may have to wait a while). Inside, you'll find the second coin between the two pipes-wall-jump or propeller into it.
Second star coin in 1-1
#3
You'll find the third coin just above a signpost on the higher route, after the red coin ring (also above the main course). Keep in mind that if you've taken the lower route that the coin may be too high to see--it's just before a trio of goombas. It can either be leapt to from the nearby platform or propeller hat'd into.
Third star coin in 1-1
World 1-2
This level is the first underground level, where the ice flower is intoducced. There are basic enemies such as goombas, koopas, and Pirahna Plants. The first star coin is located early into the level, and you can reach it when the crystal platform tilts to the left. The second star coin is in a hidden area. When you reach the controllable platform, tilt it to the right and go into the warp pipe . Once you get in, you'll see a block which has a P-Switch in it. Try not to grab any coins then hit it. The coins then become bricks, so you can hop up and get it. The third star coin is also in a hidden area, but you can see it. Once you reach a warp pipe covered in bricks, Butt-Stomp through the bricks then go in the pipe. Once you get in, you'll see a bunch of coins that you can't reach. Pick up the POW block and throw it, sending all the coins downward, and you can get the star coin.