Known Issues
The No$GBA emulator has known issues with this game. The fog in Super Demon Returns is messed up, and the portraits in the Adventure game start to glitch out after a while. There is also a strange whitening effect overall on by default.
Desmume works flawlessly but enabling OpenGL may cause issues with some of the 3D textures like Arino's crown and your main character portrait. If you have sound issues in Desmume, particularly with Arino and the announcer, set your Sound Settings to "Synchronous Mode"
Save states in general are a bad idea with this game regardless of flash cart or emulator. Restoring from a save state frequently results in a crash soon after. You have been warned.
The voice data of Arino and the Announcer are left in Japanese in the game. There is no way to add subtitles and even if we could replace the sound data with other voices, there are 1290 voice samples from Arino alone in the game and another 50 or so from the announcer. A chart is in progress explaining what each one is, though may or common grunts or off-handed comments related to the game you are playing.
The RPG (Guadia Quest Saga) and (less so the) Adventure games have a mind boggling possible number of combinations of actions, situations, items, skills and dialogues. There may exist a random combination of these that results in something unexpected. All games have been tested from beginning to end, however.
The Adventure games and RPG use a variable width font in order to fit more of the dialogue on screen (which means characters like "i" and "l" don't take up as much space on screen as "o" or "s"; there is no padding of the slimmer characters). Exact spacing and alignment down to the pixel based on this is not possible.
Magazines and Manuals use a font that supports half-width characters just fine except for the apostrophe, which is double-byte. Most punctuation is double-byte but there is a workaround. Finding a way to make the apostrophe half-width is left for a future patch. This only affects the appearance of the apostrophe and the spacing left/right of it.
How you can help
Textual errors
I need to know the exact phrase you are talking about, including all punctuation and line breaks. Even if inefficient, a screenshot helps me the most.
If that is not realistic, tell me the scene or point in the game where it happened, including the context if applicable.
Graphical glitches
Graphics are a lot harder to change and may take time for me to get to them and/or fix them. Let me know where in the game something is glitched or missing and I'll see what I can do.
If you have a suggestion for something better, please include a sample file. Please note that palettes and sizes for each image may be severely limited, so things like anti-aliasing or titles that sprawl all over the background may not be possible.
Game crashes
In most cases, it is due to text running too far over the border of the screen/window or a missing or broken control code in the text. Tell me the exact text displayed on the screen just prior to the crash.