Below, we have maps of the levels with item and enemy positions, along with short descriptions. Map key appears below the last description.

01
With the Kuribo Shoes, Spinies, and the two floors connected by pipes, this one reminds me of World 5-3. But, 5-3 started you out on the right, and only had one connecting pipe.

• Level map

02
Another level reminiscent of 5-3. The end is really interesting, due to the unfinished nature of the level. The pipe I've marked with a "*" takes you to a Coin Heaven with a treasure chest containing a Jugem's cloud at the end. When you collect it, you are taken back to the map screen. To find the real goal, you have to fly over the wall behind the pipe.

• Level map

03
This one is like 7-3 with the hills, Continuous Starmen, and Lakitu. Perhaps this was scrapped in favor of 7-3. What's with that one Coin in the middle of nowhere?

• Level map

04
A lot like 1-5, sans a Coin Heaven. Big doors at the beginning are actually two doors side-by-side.

• Level map

05
This one has a bunch of unused Tanooki Suit bonus rooms. Game Genie code YLLLLI is great for walking through the walls to check out all the rooms. Counting the pipes on the ground, numbers 4, 5, 7, and 8 take you to empty space where you eventually fall to your doom. If these were part of the real game, the pipes would take you back to the level.

• Level map

06
In the original game, this level is also accessible with Game Genie code AOZULT because the START panel on World 1's map screen had a pointer to it, and the code forces level entry. However, with the code, the colors are a bit off because other pointers are incorrect.

Inside this possible World 6 reject, annoying jumping Cheep-Cheeps and Fire Chomps show up at the most inconvenient times. The blocks dip up and down like Worlds 3-3 and 3-8.

There is actually a weird bug you can do here: As "big" Mario, jump on the middle of the moving platform. Don't move, and as you pass directly under the wood block, Mario's feet will stomp the Cheep Cheep, and then the Fire Chomp, which will force Mario off the moving platform. But wait, now Mario's standing in mid-air! The game thinks you're still on the platform, except what you're now standing on is an invisible platform about one block long, so there's nothing more you can do except walk off and fall in the water.

The goal area at the end actually goes up higher than what I've mapped, but there's nothing but the pipe up there so you're not missing anything.

• Level map

07
Argh, another auto-scrolling water level with Jelectros (7-4). The auto-scroll basically follows the Jelectro groups. Near the end, the scroll will let you get out of the water onto a small stretch of land (of mostly Munchers), then back into the water to the exit pipe.

New enemy: Gold Cheep Cheeps! They act like their green brethren, except they swim faster, and in groups. I think they were supposed to be in groups of threes; the second time they appear, they start out too close to the water surface and only two appear.

• Level map

08
Of all the "lost levels," this one is my favorite. To get to the top, you must swim up the waterfalls. Small area, no enemies.

• Level map

09
As in Worlds 3-3 and 3-8, the blocks steadily move up and down.

New enemy: Green Parabeetles! They act like the normal red ones, but move faster.

• Level map

10
Another moving-block stage like 3-3 and 3-8. More Green Parabeetles. A possible enemy-infested Coin Heaven, because the end pipe would lead back to the level.

• Level map

11
A lot of things here can be found in 1-6.

• Level map

12
A different take on #11, but a lot shorter. No exit here, except the deadly pits.

• Level map

13
Same as #12.
ROM offset: 230D4
Enemy offset: CB54

14
No enemies, no exit. The black stuff at the top of the screen is interesting; it's possible the background is supposed to be black, and those are the stars.

• Level map

15
No exit in this level either, nor any enemies to speak of except an inactive Bullet Bill cannon. Interesting stacked cloud platforms here didn't appear in the final game.

• Level map

Key
	=	Coin
	=	Brick Block
	=	Brick Block w/ Coin
	=	10-Coin Block (in Brick Block)
	=	Question Block (contains one Coin)
	=	Question Block w/ Fire Flower (Super Mushroom if "small" Mario)
	=	Question Block w/ Super Leaf (Super Mushroom if "small" Mario)
	=	Giant Question Block w/ Tanooki Suit
	=	Question Block w/ Starman
	=	Question Block w/ Continuous Starman (will contain a Coin if Mario is not invincible)
	=	Note Block
	=	Invisible Note Block (leads to Coin Heaven)
	=	Invisible Block

^Top

Unused bonus games

Here we see Hammer Brother and Koopa Troopa sprites next to Toad, who hosts the bonus games.

It looks like these two traditional Mario enemies hosted dice games for keys and coins, and another game of chance for cards. This IPS patch, made for the Japanese ROM by BMF54123, replaces World 1's map screen with spade panels allowing access to the two partially working games. Since the games are unfinished, the graphics are not 100% correct.

This Japanese text, found with the other bonus game text, would be spoken by the hosts.

The Japanese text above exists in both the US and Japanese ROM.

Found with other bonus game and map screen sprites, these additional question mark graphics may have appeared in the unused bonus games. (Picture on the right shows all the graphics.)

Bonus game info and sprites found by BMF54123.

More unused sprites

This skull was ready for the map screen, while the "P-ball" and Toad sprites may have been made for the lost bonus games.

An unused propeller found with underwater sprites.

Some unused background graphics: spikes and a wheel.

CORRECTION: Though it looks like a Toad Suit, the sprite below is actually the Hammer Suit that pops out of the big Question Block in Worlds 6-10 and 7-8.

Unused sprites above found by BMF54123.

Debug mode

The debug mode in SMB3 is unlockable via Game Genie code KKKZSPIU. (The code does not unlock the special menu screen the game testers saw, but it still works if you pay attention to the title screen.) The debug mode has five features:

• Start at any level - Press Up and Down to select from Worlds 1 through 8, then press Start and you're there! Or, on controller 2, press B + A + Down to rescue Princess Toadstool or B + A + Right to go straight to the credits.
• Start with 99 lives - Each time you press A before starting the game, five lives are added to Mario's extra-lives total. The maximum is 99 lives.
• Start with every item - On the map screen, your inventory has one of each item, with P-Wings filling in the final two boards.
• Anytime-power-ups - In a level, pressing Select upgrades Mario's power. (When Mario has the Hammer Brother Suit, pressing Select takes him back down to "small" Mario.) The best part: Hold A or B and press Select to enable/disable Kuribo's Shoe! The shoe might look a bit weird in levels it was never supposed to appear in, however (as seen in the third screen shot below).
• Unlimited time - Nothing happens when the timer runs out, and Mario can continue on.

Everything works the same for Luigi as well.