Adventure Island Hack

Download the hack here

The hack is in IPS patch format, you need the US ROM of the game and a patcher program. Full instructions at the end of the page.

A small break from the PC game

I took on a side project last week: to revisit the Adventure Island game on the NES, and see what could be done to make it more enjoyable today.

I’ve always loved playing this game. At a first look, it could be a similar game to Super Mario Bros, released 1 year before. It is a platformer, you start on the left of the screen, hold B to run, press A to jump, run to the right, jump holes, get powerups, defeat enemies. Every 4 levels you fight a boss and you go to the next world, and there are 8 of them.

But the level design is nothing like nintendo’s game. The game’s developers (not Hudson, the original programmers from Westone) made sure to always keep the game at a fast pace. It is not only possible, but encouraged by design that you run as fast as possible. You have depleting health, so you need to run to find food. There is a skateboard that practically turns the game into an autoscroller. The fruits and hazards are all positioned with the skateboard in mind so you generally don’t have to stop moving.

When you get good at the game it becomes rhythmic. At points it looks like a dance. The enemies are the leads and you follow gracefully, or face demise.

Nothing is perfect

So, what are the problems with the game? Well, for starters, it is very long. It features no warps, no save and no passwords, so you really need to beat all 32 levels in one sitting. This is made worse if you don’t even know about the continue secret, which is revealed in the game’s manual: find the hudson bee on level 1-1 and then press right+start at the game over screen. If you by mistake press anything other than right+start or wait too much you lose all your progress. Pretty daunting.

Another problem with the game is that the difficulty curve is based on variations of the same levels. You keep replaying harder versions of each level until the game is done. This was ok back then when you had only a handful of games in possession, but nowadays it is a little too much.

Finally, you die in a single hit and when you do you lose your weapon. This was really maddening, because it meant you would need to start over, without a weapon on some levels that don’t even give weapons.


How to fix it?

The most obvious modification is to cut down on repeated content. I have looked into all of the game’s levels and detected that there are 10 different “sets”. These sets may have repeated graphics, but the level layout is unique to each one of them. So cutting down to 10 levels from the original 32 was already a good idea, but one of these sets is too much like some of the other ones, so I cut it too. In the end, I have selected the following levels:

Level 1 (old 4-1)
Level 2 (old 3-2)
Level 3 (old 7-3)
Level 4 (old 7-1)
Level 5 (old 7-2)
Level 6 (old 8-3)
Level 7 (old 8-2)
Level 8 (old 8-1)
Level 9 (old 8-4) (Boss)


Notice that I changed the old 1-1, 1-2, 1-3, 1-4, 2-1, etc. format to a simple level sequence. This way you only fight the boss once.

I did this change and it was still hell to play. The game is too hard, so I had to address the other problems.

So I’ve added an automatic option to continue. And things improved. There was still the 1 hit kill problem, so I’ve changed it so you don’t die in one hit and some of the health is taken for that. It already felt like a totally different game at this point. Fairer, but still hard, as it should.

Then, I made it so you always start with the axe after dying. This removed some of the insane difficulty some of the later levels had. It was the “gradius” effect. If you die and lose all weapons you might as well just restart the whole game. Not anymore!

Finally, I made so all of the hidden power up eggs were now always visible.

Final Touches

I really liked the results, so I wanted to do that final level of polishing. I’m glad I did! I added the option to play the new level sequence using the original harder rules (no weapon, hidden eggs and 1 hit kill) or the new arranged rules.


Then, I managed to replace the original score system with a more modern, useful time attack system. During the game there is a timer where the score used to be, and speedrunners can use it to time their runs.


This led me to make a few changes to the ending screen:

  • Now the ending shows your total game time
  • It also shows how many pot bonus you’ve collected
  • And finally, it tells you if you’ve finished the game in normal mode (Higgins holds the hudson bee in his hand if you did). Advice: don’t try original mode unless you want an infuriating challenge. Arranged mode is recommended!

While digging through the game’s code I’ve learned a few things that I always wanted to know, and I found something new too.

The first thing is how the power up system works. The game has a few possible egg contents:

  • Axe: the regular weapon
  • Skateboard: protection, more speed, but can’t stop
  • White Milk: replenishes some health
  • Flower: doubles the points for each fruit for the duration of the current level
  • Fireball: a stronger weapon that can destroy rocks and reaches farther
  • Pink Milk: fully replenishes health
  • Ring: 2000 points
  • Extra life: +1 life
  • Honeygirl (looks like an angel to me): temporary invincibility
  • Eggplant (bad): drains health
  • Hudson bee (only one in the entire game): allows continuing
  • Key: makes the next falling platform rise instead, taking you to the bonus level

There was one inconsistency with this, in that some of the eggs would sometimes produce different items. I never understood why, until now.


Despite the similar look, there are various types of eggs:

  • Simple egg 1: may contain axe, skateboard or honeygirl (always visible)
  • Simple egg 2: skateboard, flower or white milk (always visible)
  • Power up egg: may contain fireball, pink milk, ring or extra life (always hidden)
  • Eggplant egg: contains eggplant (always visible)
  • Honeygirl egg: contains honeygirl
  • Hudson bee egg: contains hudson bee (always hidden)
  • Key egg: contains key (always hidden)

The way the power up egg works is this: there is a hidden power up counter that starts at 0 and goes to 5. When opening a power up egg it reads this value to determine the contents. 0 is fireball, 1 is pink milk, 2, 3 and 4 are ring, and 5 is extra life. When collecting any of these items it adds to the power up level. If you simply open the egg but don’t collect the item, it will not go up. When collecting the extra life it resets the power up level to 0. Dying also resets it to 0. The power up level is persistent between levels though. So the ring isn’t just for points as I thought for so many years, it is important to get to that extra life bonus!

One interesting thing about this egg is that it seems to directly replace the way invisible bonus worked in wonder boy arcade. In that game, at certain points you could shoot and it would reveal a letter. After revealing 3 letters the next empty spot would reveal an extra life. These letters, as it is known, are E, S and C, the first three letters of the developer, ESCAPE (now Westone).


So, when they developed the NES version they added the fireball weapon as the first of these hidden items. They then inserted the pink milk bottle here (big milk jar in Wonder Boy, attainable from eggs there). Then the letters, which in the NES became 3 rings. And finally the extra life. So, in the NES version you have a stronger weapon, but it takes two extra hidden eggs to get the extra life! These eggs are positioned in the same places as the hidden letters in the arcade Wonder Boy game.


Patching Instructions:

1- Download the hack here

2- Get your Hudson’s Adventure Island USA ROM (please legally own the game). Make a BACKUP of it!

3- Download lunar ips

4- Open lunar ips, click “Apply IPS Patch”. Locate the ips file contained in the zip.

5- Locate the Adventure Island ROM to apply the patch to.

Done! Now play it on your NES emulator of preference!

– Nesrocks

February update (I’m not dead!)

Whoa! Nearly five months have passed and I haven’t posted anything. How did I let that happen? Oh, right, I’ve been very busy working on my new game!

After studying a few game engines I had to pick one of them. At first I settled with UDK, and I had pixel perfect 2D graphics working, but in the end, it was just overkill. There are better engines dedicated to 2D games out there. I’ve tried a few, and in the end I chose YoYo Games’ GameMaker Studio. It is perfect for an intermediate programmer such as myself. And now they have released GameMaker 2 Beta which has a lot of nice features and improved performance. I can add four thousand enemies with simple AI without a frame drop on my i7 notebook! The engine is still in Beta though, so it’s not perfect, but I’m very satisfied.


About the game: there is constant progress, and I’m getting near to the point where I’ll be producing art, so it should be interesting to start showing some things. So far I’ve been working on the game’s base code and gameplay elements. I’ve got platforming movement done, ladders, swimming, jumping, a smart camera, fighting and now I’m finishing a hookshot gameplay mechanic inspired by Arumana no Kiseki, a Konami game made for the famicom!

Besides that, I have checkpoints, a cutscene system, warps, talking npcs, shaders, pausing, option screen, debugging features, a hud… With all that and along with assembly coding I did for the hack, 2016 was officially the year I did the most programming in my life. It’s been fun to learn all this stuff, but I can’t wait to go back to making pixel art. So far the game is mostly reusing the original art I did for the hack, but there will be changes (for the better).

– Nesrocks



Famicom version’s manual scanned

I’ve been working a lot on my new game. Nothing to show yet though, so in the meantime here’s the manual for the japanese version of Super Pitfall scanned for your delight. I believe the US release got a pretty close translation, but who knows, there may be some differences.


5 days to go!

Only 5 days for the release of the hack!

How far has this hack come in the last 5 months… It went from “maybe the game would be good if all items were visible, but I don’t really know how” to this. I wanna thank everyone for their invaluable feedback and support. Disch, snarfblam, jonk, Da_GPer, protomank, M-Tee, dougeff… and countless others, really. The community rocks. But I wanna thank specially macbee for the daily talks about romhacking. It was actually most of the time about my hack though, and I thought that’d be annoying, so I’m sorry about the times I talked too much! I was just very happy to be learning more about the NES everyday, and to have someone so experienced to talk to about it meant a huge deal.

Also, thanks to FCandChill for the help with the new songs and for breaking the initial barrier figuring out the sound format. It completely changed the face of the hack.

After I release the hack I’m going to move on to my PC game (wish me luck!). I plan to develop it for about 6 months, and I’m one to honor a schedule, so expect it to be released and I hope people are interested in it once it’s done. I don’t know exactly what it’ll be, but I will use my original assets from this hack, at least initially, so that gives an idea of what kind of direction I’m going to take.



Pitfall II soundtrack

The songs in Pitfall II for the atari 2600 use a special sound chip made of 100% awesome. Here’s a gameplay video to exemplify. So what better song to replace the main theme in Super Pitfall NES? hint: there isn’t a better song. So, yes, a music replacement is underway for the hack. But wait, not only that, a completely new song made by FCandChill is also going to be added! Thank you!

Pitfall II poster

Check out this amazing Pitfall II poster for the atari 2600 game. It just breathes adventure! It even has a list of actors in this action game as if it was an action movie poster. The funny bit is that it features cave rat “as himself”. Wow. I’ve always been a fan of cave rat. I gotta play this.


Unused tiles

Here we have several unused graphics from the original NES Super Pitfall. They were taken from different portions of the ROM and assembled into this single image. The image is pretty much complete in terms of unused graphics. Please note that due to how NES graphics work, the original colors were lost. These colors were chosen then for contrast.

A few comments:

  • Some of these enemies don’t exist in the final game. That’s the spider walking up walls and the spider hanging from ceiling (complete with a hanging web line tile). But others do and have updated graphics. These old enemies graphics are the same as the PC-88 version of the game!
  • The girl seems to be a beta version of the niece. This graphic remains in all areas of the game, indicating the niece could have been placed anywhere, not just the dark world.
  • The big white square can be arranged in any size, and it was found on the title screen section. Maybe a text box background, or a temporary graphics for the title.
  • Several hud icons are found indicating the diamond, the lion and the niece. There’s also a gold icon, perhaps for gold counting. And a pointing hand suitable for hud item selection.
  • There is some sort of 3 frames explosion effect.
  • The blue blob in the middle of the image doesn’t appear to be make sense in any arrangeable way.
  • The “S” is made of 4 tiles that can be arranged to form clouds exactly the same way as the PC-88 version.


Site Launched!

Hello guys and gals, it is the beginning of a new era for me. With the upcoming release of my Super Pitfall hack I’ve decided to create this blog and use it to keep you up to date with my projects.

As you may already know if you followed the thread over at, September 5th 2016 marks the 30th birthday of the original japanese release date of Super Pitfall! I plan to release the hack the day before so you can (hopefully) celebrate the game’s anniversary by playing it. Please do!