Wonder Boy in Monster Land/Round 2

Market
When you first enter the area, you can visit the boot and shield shops. Boots allow you to move faster, while shields will deflect projectiles. For now, neither is required.

After making the necessary purchases, head to the right. Extra time is located above the bricks over the water.

Caves
In the Caves, a dialogue box will appear indicating there's a secret area. Enter to collect an optional letter.

The end of the caves will have a door leading to a Vampire. It has two attacks; a swoop and a projectile volley. When defeated, you can get a broad sword. You can also jump onto the small shack to get some gold.

Cliff
Jump across from platform to platform. You can also purchase boots and healing as required.

When you reach the third level, jump to the left on the solid cloud to get coins.

Secrets

 * From the shield shop, jump to the right to get 10G.