Hey - So I initially had an earlier version of this installed. Not sure which in particular, but it was before the FMVs were available to be put on. Just last night, I installed the most recent version. Happy to have the FMVs! (I should totally downgrade them so I can see them, but still!)
Now, I essentially wound up deleting my original files and just installing all new ones, so all of my original save data is gone. That's okay, though.
So I'm playing the game again. This is one of my most favourite 3DS homebrews. Sonic CD looks genuinely amazing on 3DS, especially with stereoscope. The game seems to run fine for the most part -- with two notable exceptions so far. The first, and the smaller issue of the two, is that during the special stages, the textures of the ground won't load unless they're immediately under Sonic or directly in front of him. This was not an issue when I had the earlier version of the game. Mind you, this one isn't a big deal. I can still play the special stages, and I suck at them anyways!
The second issue is worse. The game runs totally fine from Palmtree Panic to Collision Chaos, special stages aside, but Tidal Tempest doesn't show any graphics whatsoever unless the game is paused. The game is still running; you can hear the music, you can move Sonic around, etc. It's just that the screen is completely black. If you pause the game though, you can see Sonic and his surroundings, somehow. (I'll attach a picture.)
I've tried exiting and re-entering the level, I've closed the game itself and reloaded it, and I even shut the 3DS off and back on. One time it even crashed after a reset. And I even started a second file, played through the first two levels, and once again was met with a version of Tidal Tempest where somebody forgot to pay the power bills.
Again, this was never an issue before I installed the most recent version. I'm not sure if any levels passed Tidal Tempest would be similar; the only way I could complete the level is by pausing and unpausing constantly to see where Sonic is. I ain't doing that lol.
I was wondering if anybody might know what could be going on here, and if there's a simple way I could fix it. Thank you.
edit: Oh, I should clarify a bit; the screen isn't just black. If you move around, it rapidly switches from black, to red, to white. Maybe a little neon green and purple -- it's an epileptic nightmare!
edit №2: So, it would seem the problem with Tidal Tempest is isolated to just Tidal Tempest, and also that it's all versions of all acts of the stage, as either Sonic or Tails. I used the dev menu to use stage select, and I tried out all versions of TT aside from act 3, and then I tried out the present-version first acts of Quartz Quadrant, Wacky Workbench, and Stardust Speedway. I haven't yet tried out Metallic Madness, but I assume it works fine. If it doesn't, I'll edit this post again to say so.
Side question about the game itself: Is there a way to exit debug mode after using the dev menu? Like, can I select a stage and then turn off debug so I won't be tempted to cheat?