runouw.com

1. General encounter with undeads
Boos,skelegoonies and flying skelegoonies together makes a daunting combo. You should avoid making contact with skelegoonies,whether it's jumping on them or knocking their bone wings off. Chances are,the other skelegoonie will catch you while you lose all of your momentum. The boos may look slow,but they will get dangerously close to you just when you're surrounded by skelegoonies. Spinning them away is not a good idea,as they only lift a bit higher after that,and you might get hit back. You should jump on their heads,rendering them harmless. Flying skelegoonies are even more dangerous. You might spin into one accidentally,and it will just bounce around like a giant pinball,catching you off guard. It's best to just wait for them to fly away.
2. Health Maintaining
You want to keep your focus more on killing Goombas,Shy Guys and Bob-Ombs. Avoid contact with all other enemies unless it's required. Avoid attacking Bullet Bills,too. They might suddenly counter you (The hitbox is weird).
3. What to do after getting the Metal Cap (In case you have completely forgot the hints given beforehand)
Remember the bloomeries you see on the way here? Now you have the Metal Cap,you can jump in there.
4. Battle against Mouser
Upon entry,you will see the ground booby-trapped with bob-ombs. Jump to avoid getting your legs blasted.
Wait for a second or two,and bunch of Bullet Bills will come down. Use the red ones to help you reach the higher platforms. Alternatively,you can wait a bit longer and catch the yellow missiles shot from the sides of Mouser's machine. Make your way to the top and enter the door,ending the battle.
5. Secret Pipe
The bridge to the giant crystal actually has a bit of breakable spots. Break through them and you will hit the crystals below. Press down around the closest chunk to the valley,and enjoy a major skip.
6. Red Coins
The first red coin you will see is in a room with a pendulum. Ride the pendulum and double jump to get the red coin. It's suggested to take the Metal Cap before you do this,as this can easily be messed up with the missiles chasing you around.
The second red coin is in the first bloomery you see from the beginning. Just go in the bloomery and walk a bit further. The red coin is above the door across the lava pit. The path joins up again after the door.
The third and last red coin is concealed within the ceiling chunk of the ending passage. Look carefully and you will see some breakable tiles on the ceiling. Break your way to the top and you will find a secret room with the last red coin and a Shine Sprite.