Wario Land 3/North sector

N1: Out of the Woods
The gray key is one room to the right. When you see staggered platforms, jump to the top. To reach the gray key, continue to the third right room, then go through the door at the end (at the point where you start to see a green key). Reach the top to unlock the gray chest and get the axe.

Musical coins

 * 1) Pick up a Spearhead and throw it into the throw bricks. Make your way across the breakable blocks while avoiding the Applebies to nab this coin.
 * 2) Ground pound the Futamogu until you can access the door below. Avoid the Omodonmeka and get flattened by a Count Richtertoffen after reaching the end of the room. Squeeze through the gap to get the coin.
 * 3) In the room with the leaves and the Kushimushis, swim through the water to get the coin.
 * 4) Outside of the room mentioned above, ground pound until you can hop on the leftmost Webber. Go on top of the platform to its left and platform to get the next coin.
 * 5) When you catch fire from the torch, run to the left until you see the flame bricks. When they break, jump down, and collect the coin.
 * 6) Roll on the slope and avoid the torch to break through blocks and obtain another coin.
 * 7) Jump on the Bird near the green key and platform to get a coin.
 * 8) Finally, climb the inside of the tree before becoming Fat Wario by a Doughnuteer and breaking the doughnut blocks. The coin should be at the bottom of all of them.

N2: The Peaceful Village
You can reach this area by collecting the axe in N1.

The most important enemy is the zombie. If he hits you, you will need to walk under a street lamp to revert.

The gray key is located above the start, and to the right. It requires you to either eat a doughnut or transform into a zombie. You can find the solution to the left of the key (or if you killed it, by entering and exiting the building). Once you transform, hop up the steps and drop down above the key or break the solid purple bricks. The key is in the building to the left, and you can collect a blue piece.

Gold coins

 * 1) In the left most builing, you should encoutner a robot that hits you with a hammer.  When he does, spring to the top left corner of the room.
 * 2) During night time and as a zombie, continue down before you collect the gray key (although you have to in this case.)  Revert at the lamp and collect the coin.

N3: The Vast Plain
You can reach this area by collecting the axe in N1.

One enemy will try to blind you.

To get past the sentry, get struck by an invisility potion. You won't be able to see your location until you walk through a pipe.

The gray key is to the left of the chest, and requries invisibility. The chest, however, must be opened when visible. It provides a green key piece.

Gold coins

 * 1) Directly below the gray key.  Requires invisibility.

Exits
When you get the blue and green pieces from the gray chests in N2 and N3, you will unlock W1: Desert Ruins.