GG Codes for Super Mario Land (Version 1.1) - Game Boy

[BigBossman]

I finally made my first couple of 9-digit codes after some constant testing:

Run much faster / Jump much farther
24E-CAE-193
NOTE: Mario is harder to control with this code, but you can clear huge gaps. When you hold the B button, he runs even faster. This may cause the screen to move out of sync. This will be noticeable when you quickly reach the end of a stage, however you should still be able to finish the stage.

No enemies or platforms
015-3AD-E6A
NOTE: This code removes all of the enemies, but it also removes the platforms that are vital to complete certain stages. This code is best used with the Run Faster / Jump Farther code (24E-CAE-193).

Enemies fall from the sky / Some enemies are more elevated
024-B4D

Multiple odd effects (enemies, platforms, & powerups)
056-C4D
NOTE: This causes a wide range of crazy things to happen: The fire flower slowly drifts upward, koopa troopas act weird (they seem to move real jerky), Up & down platform spawn enemies, the falling platforms fly away once they are on the screen, The boss of stage 2-3 keeps moving forward, making it easier for you to finish the stage, & fireballs from the boss on stage 1-3 changes to harmless projectiles. It'll still hurt you if you touch a fireball, but when it changes to a mushroom or falling platform, it won't hurt you.

[BigBossman]

Fireballs don't bounce off the ground
00F-DAE
NOTE: Fireballs will either go straight through the ground or will stay in place. Other times, they will bounce without any walls to bounce off of.

Mario runs slower
13D-C3E
NOTE: Mario does seem to run faster after jumping. If he is standing still & then runs, he's as slow as frozen syrup.

Enemies jump around
146-EDD
NOTE: This will cause moving platforms to disappear; Mushrooms will also fly away.

Enemies jump in place
016-EDD
NOTE: This will cause moving platforms to disappear; Mushrooms will somtimes jump, other times they jump off screen & out of reach.

Enemies & platforms don't move at all
016-ECD

[BigBossman]

I managed to find some more interesting codes:

Weird Music
01D - B39

Pass through blocks that contain power-ups when you try to hit them
BB8- 9BE
NOTE: These are any blocks that don't contain coins. This includes, mushrooms, stars, & the 1Up hearts. This also applies to hidden blocks or disguised ones. You'll pass through them if you jump to hit it, but you can land & walk on them.

Power-ups float through the air & change to different items
017-C1D
NOTE: Mushrooms generally won't change, but when you hit a block containing a flower or heart, it will start moving to the right & changing to different things. Sometimes it'll be a heart, flower, or different dead enemies. Whenever you touch it, you'll get whetever it is if its a block that normally conatins a flower & you grab it when it becomes a heart, the you get a 1-up instead of becoming Firey Mario.

Music is high pitched
35C-249

Power-up blocks only give 100 points
3FA-33D
NOTE: Except mushroom blocks. Any other block that contains the flower, heart, or star will only give you 100 points. The power-up will not come out.

Music is a series of beeps
9BD-549

Stage 1-1 loops over & over again (it never ends)
012-3DD

Removes some coins, blocks, & parts of the stage
012-50D
NOTE: This doesn't make the game hard to beat by removing vital parts. As you play you'll notice differences in the way coins are placed or unbreakable blocks are arranged.

Tiny ledges
012-5FD
NOTE: This alters the stage to the point where the ground is scattered & uneven. You have to jump from one part to another or fall. Sometimes when you fall, you won't die. If this happens, press jump & see if you can jump out of the pit & back onto a ledge. If you can't do that, push left or right & you will die. Also some parts of the stage will change when the screen starts to scroll.

[BigBossman]

More weird music
62B-28D

I'll try tweaking this next code to find something better:
Most enemies won't die with just 1 fireball hit
A55-28D
NOTE: This make enemies more resistant to fireball attacks. It took 18 fireballs to kill a goomba & 2 to kill a koopa troopa. Some of the enemies that normally take 2 fireballs to kill, usually take about 36.

[BigBossman]

Multiple fireballs required to kill most enemies
A55-28D
NOTE: Goombas typically take about 30 hits from a fireball & Koopa Troopas take about 2.

Add platforms by jumping
347-E9E
NOTE: When you jump, you'll notice that you'll leave a trail. If you keep jumping in that same place, the trail will change shapes & eventually, you'll have a platform you can jump on. Also is you have one foot off a ledge, in a few seconds there will be a ledge to walk on.

Come across enemies & obstacles sooner
6D8-36F
NOTE: This causes an enormous gap at the start of Stage 1-1. After clearing the gap, you'll notice that enemies appear to be out of place. The moving platforms also are further up from where they are normally.

Platforms appear at regualr intervals on Stage 1-1
B43-349

Bolder stage colors (scenerey)
015-EBF
NOTE: Best used with a Super Gameboy, but works on the original Gameboy. This causes the colors to appear much darker & brighter. On the Super Gameboy, the reds appear so much darker.

Stages appear sandy
BD4-32D
NOTE: This is noticeable from Stage 1-3 on.

[BigBossman]

No power-ups from blocks
842-05D
NOTE: No mushrooms, Flowers, or Stars will appear. There will only be coins where they normally are.

[Vallenatero2016]

A clarification to Azathoth about the Game Genie code of Infinite Lives of Super Mario Land (Game Boy).

Super Mario Land (World):

21C-4AE-4C1: Infinite lives

Super Mario Land (World) (Rev A):

21C-53E-4C1: Infinite lives

Thank you.