New Super Luigi U: Acorn Plains- Castle -- Lemmy's Lights-Out Castle

The castle is dark, but has overhead lights that swing. Some of them move with the pendulums in the castle. The first Star Coin is over a high pendulum that swings over another. There's a Red Coin Ring that makes Red Coins appear over the pendulums swinging over the gap. Collecting them all will give you a 1-up or an Acorn Mushroom. You'll need it to reach the second Star Coin, which is below a pendulum. Drop down to get it, then boost to safety. Over solid ground are a set of three brick blocks. The middle one contains a P-Switch. This will turn the coins into brick blocks so you can safely travel over the Nippers. Drop down into the gap between two sets of Nippers for a pipe. This leads to the third Star Coin, over a pendulum. The boss door is ahead. There's an 8-bit Luigi on the right wall. Going through the boss door will add 100 seconds to your time. Launch from the cannon to the Airship. Lemmy stands on a bouncy ball and tosses bombs. Stomp him three times to defeat him. You'll open the path to Layer-Cake Desert. You'll also get a message saying that you've collected all the Star Coins, which should mean something good. Save your game.