I have downloaded and played all three versions of Fire 'N Ice, so I can tell you the differences.

The only difference between Fire 'N Ice and Solomon's Key 2 (European Version) is the title screen, everything else is exactly the same. Even save states from one version work in the other version. The only exception is on the title screen, where the title has a glitchy sprite, but the game can still start.

There are plenty of differences between Fire 'N Ice and Solomon No Kagi - Coolmintou Kyuushutsu Sakusen, the japanese version of the game, though.

1. The title screen looks different

2. The text is written in Japanese, everywhere except inside the levels.

3. There are the options to save, load, play, edit, and copy up to 22 levels in the level editor.

4. There are 3 save files to choose from instead of the password-based system.

Because of this, save states do not work between the other two versions and this one, resulting in frozen screens that do not let you do any inputs, and glitchy titles.

The differences between all the versions won't affect the gameplay at all, so I think they can be combined into one category.

The images below show the normal titles for each version, and the glitchy titles for when you load the other version's save state, in case you're curious what I mean by "glitchy titles", and the title differences.

Another category idea I have is individual worlds, like just world 1, just world 2, etc. You could use the right password to start at world 10, and just move to the right world on the map for worlds 1 through 9. Timing could start on entering the first level, and end when Dana does the little dance for finishing the 10th level. This run is a lot shorter than the main run, but I think it's still long enough to be competitive. On the other hand, individual levels are too short to be competitive, especially for the earlier levels where everyone goes through the fastest path to beat the level, and it would just end up with everyone being tied for the record.

Emulators are allowed, and it's in the same category, it just has a label next to it saying that the run was done on an emulator. In fact, all of the top three runners use emulators, and I will as well once I upload a run. I don't know the specifics of what emulators are recommended and I don't know what Mesen is, but I think any emulator would work fine.

Okay, that makes sense! Maybe once I actually finish playing the bonus levels I'll see for myself how they feel like leftover stages that aren't worth learning for the run. I can only play the game once a week, and I'll need a couple more sessions to finish my first playthrough, but then I might do a couple of practice runs and upload a time about a month from now or later.

Since there are fifty bonus levels you can reach by holding select and pressing B 10 times in a row on the start screen, there should be a new category for doing the whole game as well as the fifty bonus levels. It could be called 150 Levels, 100%, Any% + Bonus, or something of that sort. I haven't finished any of the bonus levels, and I haven't actually finished the game or done any speedruns, but I'm planning to soon, so I think it could be a cool category. You could also have a category for just all 50 bonus levels if you want, which could be called Bonus%.