I support this.

I am Spanish but mostly play games in English so I wouldn't be personally affected. However, many more people would play the game if at least the text was in Spanish. The audio can remain in either English or Japanese if hiring voice actors was a problem at the beginning, although it should also be translated in the medium/long term, maybe by steps.

Also it's not only Spain that speaks Spanish, but basically all of Latin America. Even Brazil has Spanish as a 2nd language over English, at least from my understanding.