How to clear Ghost House Stage, also known as Pumpkin Zone Level 3, in Super Mario Land 2: 6 Golden Coins.

How to Clear Ghost House Stage
Go to the right, and there are five ? Blocks, each of which contains a coin. There is also a Ghost Goomba floating up and down toward you.
To the right, go up the third pipe from the left to reach an area with some coins. You can go down the rightmost pipe or the second pipe from the left, but make sure there isn't a Ghost Goomba beneath the pipe.
To the right, there are some flashing blocks, three ? Blocks, and another ? Block above that, where you can get a Carrot. There is a Boo ghost on the right side of this area.
Go to the right, until you are to the right of the Boo ghost above, then jump up through the thin wooden platforms. At the top, go to the right, avoid the Boo ghost, and make your way downward on the platforms.
To the right, there are four coins above a hole in the floor. If you fall down, you can just jump back up on the wooden platforms.
The second set of four coins has some moving platforms beneath them that you can use if you fall.
If you want a Fire Flower, be aware that you won't be able to reach the Secret Goal if you get it. But if you do want it, you can go down the hole beneath the third set of coins and hit the ? Block there to get the Fire Flower, then jump back up on the flashing blocks.
The fourth set of coins has a Ghost Goomba flying through them. Try not to fall into the hole beneath the fourth set of coins, because you have hit a lot of Hidden Blocks down below to get back up.
The fifth set of coins just has wooden platforms in the hole beneath them.
After that, go to the right. There is a pipe with a Venus Fire Trap, followed by a pipe with nothing in it. If you are tall, go down that pipe (you need to be able to break Bricks when you hit them). You can get power-ups in this area, but there are Hidden Blocks that you need to avoid hitting, or they will prevent you from getting the power-ups. First, hit the rightmost brick, then jump on top of the brick that is to the left of the one that you hit. From there, hit the ? Blocks above. The rightmost block contains a Fire Flower (but you won't be able to reach the Secret Goal if you get it). Then jump on top of those Blocks, then hit the middle Brick. Jump up through the hole and hit the ? Blocks there. The rightmost block contains a 1-Up Heart.
Then go back down the holes in the bricks and go back up the pipe. Hit the Midway Bell.
Then go to the right, and there is an area with spikes in the ground and flashing blocks above them, as well as Boo ghosts. Make your way carefully across the flashing blocks, and turn to face the ghosts to stop them from chasing you.
At the end of the area with spikes, jump on the brick wall on the right.
Go to the right from there, but before you start going down the wooden platforms, if you're still Bunny Mario, you can do a running jump, then hover to the right to reach a platform. Go to the right, past the two Ghost Goombas, to reach the Secret Goal and unlock the Pumpkin Zone Secret Stage 2.
Otherwise, just go down the wooden platforms. At the end, there are some flashing blocks, and an arrow made of coins, which is a hint that the Secret Goal is in that direction (but you can only reach it if you're Bunny Mario). Jump up the flashing blocks and hit the Bonus Bell to complete the level. You will play Mario Catcher if you hit the bell.
After the Level
If you unlocked Pumpkin Zone Secret Stage 2, you can go there next. If you went through the normal Goal Door, you can continue on to Witch's House Stage.
Or you can go to any of the other zones: