Kirby: Nightmare in Dream Land has a total of several different worlds, or levels to complete. None of the levels themselves are really difficult to complete. They get a little harder as you progress but nothing extreme. At the end of each level there will be a boss to fight. There are also things called switches in some of the worlds, which open up new areas and allow you to complete the game 100%.
 1. Vegetable Valley
This world is obviously the easiest in the game. The scenery is mainly lush and green plant life and forests. The enemies are all pretty basic too. The boss is Whispy Woods, who is very easy to defeat. If you have an ability, go up next to him and attack. If you don't, just spit back apples at him. Vegetable Valley has no switches, so completing the level will be very straight forward.
 Stage 1-1:
Room One: You'll appear in a meadow type area. Just keep walking forward until you come across Waddle Doo (the enemy with a huge eye). Swallow him up to get the beam ability. Just keep going, and use your beam to get rid of all enemies in your way. You should reach the door soon, go through it.
Room Two: This room looks kind of like a mountain region. Just go forward past the waterfall to the next doorway. (There may be a small dark spot in the waterfall. If you see it, try to go through it and you will find a UFO Enemy.)
Room Three: Continue walking forward and you'll reach another waterfall. This one has a Maximum Tomato at the bottom. Get that, and go forward until you reach the final doorway.
- Completing this stage opens up the Bomb Rally Mini Game.
 Stage 1-2:
Room One: Head forward, and jump over any enemies (unless you have an ability) until you reach Waddle Doo. Swallow him up and keep going until you reach the warp star. Hop on.
Room Two: You'll notice a line of Bronto Burts. Get close to them and they'll fly away, or just zap them with your beam. You're now coming across your first mini boss. If you want to use your beam, get close to him, shoot him, then run away. If not, get rid of your ability. When he spits out bombs at you, inhale them, and then spit them back out at him. This boss shouldn't take long. If you want the crash ability, swallow the boss. But if not, just keep going. After two more Bronto Burts you'll reach the door.
Room Three: If you have an ability then destroy the enemies that are walking up to you. If not, go ahead and swallow Hothead. Go ahead and jump over the pool of water and continue defeating your enemies. Soon you'll come to a place where you can either go above or below. Go below first and destroy a few star blocks to get a Maximum Tomato. Then go above to reach the door.
Room Four: Avoid the spikes on the ground, and continue destroying your enemies as you travel upwards. Soon you'll reach a Sword Knight. Get rid of him quickly, then go through the final doorway.
 Stage 1-3
Room One: You'll first be in meadow like environment. Deal with the few enemies in front of you first. Then, float towards the top of the screen and move across the area quickly. If you stay in one place for too long you risk getting hit by a bullet. After that, just keep moving along and you'll come to the door.
Room Two: Go ahead and swallow up one of the burning enemies right away, then kill the one you didn't swallow. Now every time you approach a waterfall, wait until the Bronto Burt flies up a little then burn-dash right through it. Keep doing this a few times as you travel across the area and you'll find the door.
Room Three: Travel downwards, killing any enemies if necessary. You'll reach a small pool of water. Quickly deal with the enemies in the water, then swim to the doorway.
Room Four: If you still have your burning ability, just dash through the enemies, killing anything in your way. Soon enough you'll come to a maze type thing. Go over the top of it. Once you reach the other side, go right on the bottom passageway. You'll find a Maximum Tomato. Continue going left until you reach the final door.
- You'll unlock your first Kirby Museum with the Sword ability inside. Take it if you'd like to.