A few additional hacks sourced from other recent MAME dumps, each of which have some fairly interesting backgrounds:

*Anger Bird 2 (Flipull hack) - This hack originates from the "Play Vision Portable" systems, and was denoted as becoming unplayable after level 4. Going by the ROM itself, this appears to be the result of a poorly-done MMC3 hack; I re-converted the hack's elements to a cleaner MMC3 port of Flipull, thus allowing the game to be fully playable.
*Game Mars of JJ (Super Mario Bros. hack) - A recently-developed variant of Frog Prince that was designed for the "W1 Mini Retro Chick", a handheld modeled after a chicken, for some reason. The hack uses the same chicken as the outer handheld itself.
*Tag Team WWF Smackdown (Tag Team Pro-Wrestling hack) - Generic title screen hack, though it previously appeared on the common 200-in-1 plug & plays with "WWF" ripped off of the title (making it just "Tag Team Smackdown"). I vaguely recall some early 200-in-1 models retaining the WWF logo, though I don't think any dumped revisions retain it.

This may not be the most elegant analysis, but I recently attempted to fix the PCM issue present in games from the unknown set of five 8-bit games (which are speculated to originate from zhengyaxin_8bit). This game set includes Fruit Pig, Eeeck! A Mouse, Echo Chamber, Sudoku, and Trounce; fixed ROMs are provided for the former two.

All of the games in this set repurpose their sound engine from Parasol Henbee; more specifically, they literally copy the entirety of bytes 18010-1C00F from Parasol Henbee (containing all music and sound effects), with no code alteration whatsoever. Seemingly because of this, something within the code results in a bunch of static-like sound coming out of the PCM channel, which is not present in the Parasol Henbee tracks themselves. This is especially egregious in Fruit Pig, in which the entire game sounds heavily muffled.

Further connected to this issue is another oddity; all of the games (save for Sudoku) feature a blank PRG area of 2000 bytes. As far as I can tell, the blank areas are merely intended to mask further PCM output; as filling them with code can further worsen the audio. While I'm not 100% certain on this, I suspect that this is also why Fruit Pig's audio is worse than the others; as its blank area is from 6010-700F, while the other games hold it in 4010-600F. (While entirely unrelated, this also means that the games are effectively only 8K in size outside of audio...)

In Fruit Pig and Eeeck! A Mouse, I was able to reduce the PCM playback by zeroing-out some of the sound channels. There is still some level of PCM present, though it is drastically improved regardless. Unfortunately, this solution did not work for the other games; I was able to reduce Trounce's playback by putting a row of eight "FF" tiles from 4090-4097, though I assume this to not be an ideal code fix (and haven't attached it as such). The sound issue is negligible in Echo Chamber and Sudoku to begin with, so I don't feel a fix is needed for them anyway.

As an additional side note, for whatever reason, Eeeck! A Mouse effectively "plays itself" in some emulators, registering random inputs in-game. Furthermore, Fruit Pig will skip the opening win condition screen, which I suspect is a similar input issue. Both issues miraculously fixed themselves upon muting the audio channels; so that's just an extra benefit, I suppose...

This thread exists to catalog most of the debug stuff I've found in Gamtec games. These range from music/SFX test screens, stage select screens, to debug info shown during gameplay or RAM viewers. These aren't meant to be accessible normally since they're either dead code (not jumped to or called at all) or behind a RAM value that never gets set.

To start this thread off, here's a screenshot of the stage select from Pocket Monsters. This screen also exists in other games made with the Mulan platforming engine (excluding the Donkey Kong games). The text itself is stored in ASCII inside the ROM and is displayed with the Sonic the Hedgehog debug font, which is probably the first time the font ever gets used since its first appearance in the ROM of Tekken 2

You can access it in Pocket Monsters using the Game Genie cheat codes: RE3T-C614+RE3T-C616+RE4A-C6TY+RE4A-C6T0

Does anyone have the extracted SD card contents of the "Retro Arcade FC A6Plus - 8Bt Game Console" (ROM name "a6plus")? According to MAME, the console uses a VT369 menu interface, but reads most of its games off of a MicroSD card. Going by a Reddit post, the games seem to be standard .nes files, albeit very poorly-named (https://www.reddit.com/r/Handhelds/comments/1bu06a1/what_the_heck_is_this_aliexp_mini_arcade_with_tf/).

If the game list beginning ~FA400 in the ROM is accurate, it appears that a number of games are rare (e.g. Air Raider, Pikachu5) or potentially undocumented (e.g. "Bomb-Mar", "Video Player"). The ROM itself does contain ~6MB of Nice Code games (some being Qi Sheng Long variants), but I did not see anything undumped at a cursory glance.

A 3-in-1 multicart this time, including only self-made ROM Hacks.



The cart includes:

== LIST ==

01. Kart ViiN (Zippy Race hack)



It's Zippy Race... But it's Mario Kart! You race as Mario instead of a bike and the cars have been replaced with Goombas on a kart.

02. Crash Bash 6 (Mappy Hack)



This hack of Mappy features Crash Bandicoot as the main character. Despite the name, it has nothing to do with Crash Bash for the PlayStation. Some graphics are from Mario Bros, Bomberman, Lode Runner, The Adventures of Dino Riki, and Nuts & Milk. And also the Grem sprites from Samurai Iroha were reused in this hack.

03. Little Einstein (Lode Runner Hack)



So remeber that educational cartoon that aired on Playhouse Disney back in the mid-2000's? It's on the NES now, and it's a Lode Runner hack! In this hack you play as Leo from the cartoon itself, and various graphics and palettes were changed. The enemies sprites were taken from Kirby's Adventures.

== END OF THE LIST ==

All the hacks in this multicart uses Streets of Rage 2 font as the main font, except on the menu.