There is no "l" in Japanese, only "r". So you can't write "Splatoon", only "Spratoon". Obviously Google Translate will use an "r". But you read it as "Splatoon", like the western name.
(Not sure if serious, but a quick explanation can't hurt anyone ^^)
I was serious, but now that i recall i've heard that before! thanks for reminding me haha xD ....
*backs off sweating like an idiot*