New Super Mario Bros.: 6-3

This level takes us back to the jungle. Some of the item blocks are red now, have spikes, and rotate. Hit them when the spikes are pointed away. Fire Piranhas are also here. After the first set of pipes, there's an item block dangling from a string that's bouncing under the 1st Star Coin. Hit the item block, then jump off it to get the 1st Star Coin. Go down the red pipe to find a log that spins in purple water. It will dump you into the purple water if you stand on it too long, so keep jumping and moving. There are some Red Coins down here. Go up the pipe to the right, avoid the Piranha Plants and go down the second green pipe from the red pipe for the 2nd Star Coin. Come back up the same pipe and go down the last green pipe in the area. Go up the green pipe at the end of that area, which has some coins. You'll soon reach the midpoint. There's a lone coin on the ground, which turns out to be a Moneybag. Chase it down for coins, if you like. Towards the end, go up, over, and left to get the 3rd Star Coin. The flag is nearby.