This is the 1997 version. Changes are highlighted in mermaid turquoise. I wasn't happy about removing the ね from the first line, because it takes it further away from the English "isn't it neat?", but more than that, I wanted to keep the rhyme, so change it did. Disclaimer: I'm not a native speaker, nor fluent in Japanese in any sense of the word.
よう見てみ、めちゃステキ
you mitemi, mecha suteki
Have a look at this. It's so wonderful!
これでもっとかんぺき
kore de motto kanpeki
This is even more perfect.
なんでも持ってんねん あたしは全て
nandemo mottennen atashi wa subete
I have everything, I have it all.
まわり中取り囲む
mawari chuu torikakomu
All around me are
なんてようさんの宝物
nante yousan no takaramono
loads of treasures.
陸にあるもん 全部手に入れた
riku ni arumon zenbu te ni ireta
I collected all these things from the land above.
何に使うものかも知れへんの名前も
nani ni tsukau mono kamo shirehen no namae mo
I don't know what you use this for, or even what it's called.
なぁ、これほしい？二十個もあるん
naa, kore hoshii? nijuuko mo arun
Hey, you want this? I have 20.
やけど 足りへん何か
yakedo tarihen nanika
But I need something more.
人間の住む国で
ningen no sumu kuni de
In the land where the humans live,
見たいなステキなダンス
mitai na suteki na dansu
there are wonderful dances that I want to see.
そして歩くなんてゆうた？あぁ、足！
soshite aruku nante yuuta? Aa, ashi!
And walking with — what do you call them? Oh, feet!
鰭じゃ遠くへ行かれへん
hire ja tooku e yukarehen
You can't go very far with fins.
足がいるわ踊ったり
ashi ga iru wa odottari
You need legs to do things like dance
散歩したり どこを歩くんだっけ？道！
sanpo shitari doko o arukun dakke? michi!
and stroll — Where do they walk again? Streets!
歩いて、走って、日の光浴びながら
aruite, hashitte, hi no hikari abi nagara
Walking, running, while basking in the sunlight.
自由に人間の世界で
jiyuu ni ningen no sekai de
Freely, in the land of the humans.
なんでもあげるわここを出て
nandemo ageru wa koko o dete
I would give anything to leave here
ぬくい砂の上で眠れたら
nukui suna no ue de nemuretara
and sleep on the warm sand.
陸にはいないわ あんなわからずやは
riku ni wa inai wa, anna wakarazuya wa
On land, they don't have such stubborn people.
あたしは子供やあれへんで！
atashi wa kodomo ya arehende!
I'm not a kid!
あ〜、わかれへんことようさん！
a~ wakarehen koto yousan!
Oh, there's so much I don't know!
教えてほしいことようさん！
oshiete hoshii koto yousan!
There's so much I want to learn!
なんで火は燃えるの教えといて
nande hi wa moeru no oshietoite!
Tell me why fire burns!
いつの日か陸の世界の果てまでも
itsuno hi ka riku no sekai no hate made mo
One day, I want to travel across the world above
行きたい 人間の世界へ
yukitai ningen no sekai e
to the land of the humans