There are a lot of levels / planets (in case of JJ1) that their name gives a lot of trouble - how to spell it and how to pronounce it? As I have no idea of how to pronounce them and I have no intention to create a youtube channel where I could record my guesses, I will list all the correct spellings (at least the ones I know). Of course only of the confusing ones, the extra confusing ones are in big size:

Tubelectric, which in JJ2 somehow became Tube Electric, but originally the two words were merged in JJ1. Exactely the same case as with Megairbase.

Turtemple, not Turtlemple.

Nippius, with double "p".

Marbelara, not Marbleara.

Sluggion, with double "g"!

Dreempipes, not Dreampipes!! This is probably one of the most problematic, as majority tend to think it comes from words "Dream Pipes". It would make sense, but for some reason it is "Dreem Pipes", whaever "dreem" means...

Pezrock, not Pezrox.

Crysilis, not Chrysilis, nor Crisilis, Chrisilis etc.

Muckamuk, not Muckamok... The vast majority writes Muckamok, even Haze did so in his coversions of that planet.

Raneforus, not Rainforus or Rainforest (?). Which would be really weird because the orginal planet is more a jungle that a forest and I don't remember any rain there (I believe the only rainy planet was Medivo).

Holidaius, not Holidaeus - which I've even seen Violet CLM himself spelling that planet like this.

Bloxonius, not Bloxinius.

Carrottus - now here I'm not sure... Some of the files have the spelling with 2 "t"s, but the original music files included in JJ2 are spelled only with one "t"...

Colonius, this is the correct full name, not Colon or Colony.

Psych, does this have any lager name?

I believe that's it.