Basics - New Super Mario Wii Guide - IGN

Some levels have secret goals -- they look like red versions of the flags at the end of a level -- which lead to Warp Cannons, Mushroom Houses, secret levels

Secret Goals - New Super Mario Wii Guide - IGN

Super Mario Bros. - Wikipedia

Wish I could say I'm shocked, but, that's IGN for ya. : r/MarioRPG

New Super Mario Bros. Wii Game Guide

Super Mario Bros. 2 - Wikipedia

Basics - New Super Mario Wii Guide - IGN

Super Mario Bros. Wonder Guide - IGN

Basics - New Super Mario Wii Guide - IGN

World 5 - New Super Mario Wii Guide - IGN

World 2-4 - New Super Mario Wii Guide - IGN

World 6-2 - New Super Mario Wii Guide - IGN