World 1 serves as a tutorial level, but contains a few hazards and enemies. To complete it, head all the way to the right, collect the key, and go to the exit.
The first set of crates you see will obscure coins. Kick these crates to uncover the coins, and collect them. They are useful in the shop.
The shop contains only a few items. You can purchase bombs, a feather, or life restoration. The other items are out of stock, and would be too expensive to purchase even at this stage.
After the shop is a picture of a man, which can be collected to restore life.
The key is locates within the cave near the exit, and is entered from the right. Enemies may be roaming around; to defeat them, use bombs or kick the crate down from the platform above.
If you want to collect more coins, jump onto the platform near the exit, and head to the top-right of the map. The chest can be kicked to release two coins and can also heal you.