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TMNT 2 (NES) - Options mode

Started by nesrocks, April 04, 2021, 04:03:02 PM

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Hey everyone, long time no new threads from me :) Here's one!

I have released version 1.0 of my options mode hack for TMNT 2.
It adds an option mode where you can listen to the music, change initial lives and continues, and you can select the difficulty from easy, normal and hard. These currently only change the amount of damage taken.

Currently unreleased is that I've improved it further with a harder "mania" mode for more damage received. Also, I have included a feature that changes enemies agressiveness depending on the difficulty. The goal is to keep the "normal" setting identical to the original game.

One thing that I thought to do is to add a "combat" option: "original" and "reworked". I have this partially working. It adds more HP to enemies but you can now attack them consecutively, as in, they don't get invincibility time. So a regular "combo" would be one or two normal attacks and then a special. I'm thinking that in this mode foot soldiers should have HP based on their class. In the original game every foot soldier has the same HP (kill in one special attack). It would be interesting to have that changed.

It has been suggested to add an "easiest" difficulty too, where regular enemies only have 1 hp. Good idea?

Any more ideas for options?


I know it's not related to the purpose of your patch, but it would be cool if you replaced the Ultra logo with the Konami logo.

BTW, I was wondering if you know if your patch is 100% compatible with the hack TMNT2 - Bugfix & Polish
Linktree  | Better a small finished project than a thousand giant ideas stuck in your system.


I actually thought of changing the logo! ;D Maybe I'll create a patch for that.
Yeah, EthansDreamLand sent me a pm requesting it to be compatible with that hack. I've just finished making the adjustments for that to be possible (currently unpublished). When I'm done making the mania mode and the new combat option I'll release it.

So, patching order should be:
1 - TMNT II - The Arcade Game Revamped (optional)
2 - TMNT2 - Bugfix & Polish (optional)
3 - TMNT 2 - Options mode

(seems like we can't agree on how to write "TMNT2")

edit: konami logo done for raw original TMNT 2 ROM.


Very cool; will it also be compatible with the Turtle Swap hack?
I once wrote a blog.  Maybe you'll find something in it useful?


I don't think it's worth the effort for now. Too many address overlaps, and there isn't really any difference between the turtles...

I've found code that indicates konami wanted to have different hp to enemies, but not as anyone would think. The data in the ROM is based on which stage you're at. It's all working in the original ROM, but every stage gives enemies 04 health (the entire table is just a lot of 04s). I'm trying to change this to enemy type based when using the new fighting option.


These patches are great and have really helped the quality of this game.  Out of curiosity, is it possible to remove the repeating parts of stages in order to get the game closer to the Arcade?

For example, in stage 1 in the arcade, there is only 1 giant metal ball and 1 set of stairs. In the NES version, there are two to artificially lengthen the stage.


Hey, good work! I hope the RAM map I shared was of help.


Great, I didn't know you were planning to work on the title screen as well, it looks fantastic :beer:

Would it be possible to restore the highscore table?

And you could still keep the credits by adding them to the new menu of options

On the other hand, what will the "combat option" consist of? Maybe it's like a "mode B"? or maybe something similar to a "Boss Rush". like the one in TMNT3 Arena? or do you plan to do something totally different?
Linktree  | Better a small finished project than a thousand giant ideas stuck in your system.


@avlon Yeah, it's possible to cut stages, but probably something for a different patch since I want this to include the original game intact through the options. I think this would require levels to be duplicated in the ROM and I haven't studied level data size to know if there's enough free ROM for this.

@Ness Very helpful indeed! Thank you!

@sics I haven't checked about high scores, but keep in mind that in the US version there's no two trailing zeroes.
I have thought of moving the credit to the options screen, yep! Your layout is nice and might be possible if I remove some unused letters from the CHR page so those outline tiles can be added, but we need to keep in mind overscan safe zones. Things are too close to the top and bottom of the screen there.
The combat options is described in the first post. I've renamed it to "FIGHTING" (NEW or OLD). When this is set to NEW, you can hit the same enemy twice, there's no invincibility time to it, and each enemy type has their own HP. Already working, I'm doing a playthrough to test it.

I've now studied every enemy/boss hps and here are the addresses:
1886 Turret (0A)
6c24 Roadkill (10)
7454 Mouser (03)
13638 Helicopter (10)
18376 Rocksteady in 1p mode (40)
1837c Rocksteady in 2p mode (60)
18c2c Bebop in 1p mode (50)
18c32 Bebop in 2p mode (70)
19899 Fly Baxter (50)
192ea Baxter (64)
1a338 Tubulars (06) (the robot flies)
1a949 Granitor (BE) (the blue rock boss)
1b364 Traag hp (96) (the red rock boss)
1b76E Krang hp (DC)
2c14E Shredder hp (B0)
2c156 Fake Shredder 1 hp (10) (regular fake shredder)
2c15D Fake Shredder 2 hp (20) (seems to appear when real one is almost dying)
2cd4a Ninja hp (08) (the hopping, kunai throwing enemy)
2d61e Frosty hp (0A) (the snowman)
2dbf4 Shogun hp (50) (the samurai boss)
2e550 Tora hp in 1p mode (70) (the polar bear boss)
2e556 Tora hp in 2p mode (90)
2ee1d Vincent Van Growl hp (18) (the tiger)
2f392 Venom hp (0C) (the scorpion)

14650 table for every foot soldier's hp based on which stage you're at (00-0C)
04 04 04 04 04 04 04 04 04 04 04 04 04

So, interestingly, only Bebop, Rocksteady and the Tora (Polar Bear boss) have their hp based on whether it's 1p or 2p mode. Lazyness to add that to the other bosses?


Excuse me, I know it's not directly related, but could you go a bit deeper about the "overscan safe zones", it's not the first time I hear another professional referring to them and the truth, considering that many videogames make use of practically the whole screen, if not all, I'm a bit confused about it ;)

Linktree  | Better a small finished project than a thousand giant ideas stuck in your system.


Double Dragon is okay there. It has no important information on the unsafe zone. Solbrain's exit option should be positioned higher on the screen. Yes, many games had this problem, probably the devs didn't know better and based the graphics only on their test tv sets.

There's also a design aspect to consider. Something too close to the edge will often look weird. So either a clear margin or a "bleed" graphic (when the graphic seems to continue out of the canvas, as in the case of the Double Dragon title screen) are aesthetically more pleasing.


Thank you very much, this information is very useful :thumbsup:

Linktree  | Better a small finished project than a thousand giant ideas stuck in your system.


I have fixed the scrolling. Konami's games tend to have a problem with that, and in this particular game this has bugged me for 30 years.
Here's how it works now:

This is how the options screen looks. There was some technical difficulty due to the game's nametable loader and compressed nams to get the complete outlines, so this is the compromise.

I've noticed a bug in the game. Whenever you're invincible and you do a normal attack, it'll be slowed down by a factor of 2. This slow attack connects twice to enemies. I was thinking this was a bug I introduced by accident but nope. It's in the original game.


Don't worry it's understandable, since I started modifying title screens in nes, only in Solbrain I came across a type of structure that allowed to represent vertical lines, without the need to define sprite by sprite :thumbsup:
Linktree  | Better a small finished project than a thousand giant ideas stuck in your system.


I have found a small bug on the RLE nametable routine I wrote just for the options screen. It might be possible to do the entire outline.


@nesrocks - Thanks for satisfying my curiosity regarding the length of the NES stages. The more polished and closer to the arcade that this game gets, the better. Appreciate your efforts!


Would anyone like to test the current state of the hack?
It's 99% bugfree from what I can tell. It's balanced enough that I can release for testers and it's feature complete (I have a few crazy ideas but they're not for now). The only bug I know of is when you're scrolling and get knocked away to the left causing you to warp to the right side of the screen.
Patch v1.10

edit: scrolling bug fixed. also, tested and fixed the new scrolling for 2 players.
Patch v1.11


Quickly tested v1.11 for 2 stages on mania and hadn't encountered any bugs(will play more later). Everything seems to work as intended :thumbsup:
As for suggestions - make purple foot ninjas throw dynamite, but not shurikens, like in arcade, red one throws them. And place in same-ish way they placed in arcade. Also wanted those red mousers, which were on arcade. Not that they are any different in behavior(maybe they had more HP, not sure), but you can make them shoot lasers like they do in GBA game.
And of course I'm curious about crazy stuff you mentioned :laugh: Who wouldn't? ::) Unique specials and throws like in TMNT3? Run like in TMNT:TF? Those are cool possibilities of something not to expect usually, but when it's "crazy" we are talking about... :crazy:


I think there's a bug with enemy colors. Sometimes the regular purple foot soldier will appear blue or red, but behave like regular purple puncher, just the wrong color.

So, change the dynamite thrower color to red to match the arcade. Could be simple. Although the dynamite throwers from behind the wall are purple in the arcade
Change mouser detail color from blue to red to match the arcade. Could be simple too. Although there are blue mousers on the arcade that don't shoot lasers? Sounds like an arcade region thing, I'm watching a longplay and they are all blue, but I do remember seeing them red.
In the arcade the one that throws knives is white, not blue.
Placement: not so simple, haven't figured out enemy placement yet, seemed a bit complicated.
Mousers shooting lasers: complicated XD
I think these aesthetic changes or arcade like changes should be a sepparate patch, they don't go in the direction of the Options menu patch. But I'm not sure I see too much value in those because the differences between the NES and arcade versions are so big that those are just very minor details by comparison.

I did think about a running move. This game kinda wants that. But anything that adds more graphics is out of the question for me, since all CHR pages are packed and I don't want to expand the ROM.

I wanted to fix the 2 hit single move bug when you're spawning. I couldn't figure it out.

The crazy ideas are for the "new" fighting option, but too crazy for me for now:
Add that slow normal attack that connects twice to the arsenal by pressing down+attack.
Or... Add a combo system. B B B B = "normal attack #1, normal attack #1, slowed down normal atk #2 (that connects twice), special". Enemy based, as any other beat em up, meaning each time the move connects to the same enemy then the next one is the next on the combo. If it misses, then the combo resets. It would require a lot of room for new code and that's annoying to do when you're trying to keep compatibility with other hacks. And it would require understanding the 2 hit normal attack bug, which I couldn't.

The game has partial support for 4 enemies on the screen, but the fourth one will just run away and never attack. They probably decided to have max 3 instead of fixing that before release.


I've meant purple with dynamites and red with shurikens. On NES purple do both.
Red mousers appearing around Baxter on arcade and I've never noticed any difference besides color. On GBA red ones are shooting lasers similar to wheel-bots(and still can bite too), so they are more interesting.
Yeah, run would be great, but too much effort :(
Hope you'll find out the way to solve 2-hit bug. Looking forward to what'll crazy stuff you'll be able to pull :thumbsup: