Wikipedia is useless.
Ive never, ever heard anyone pronounce it ee-ko. Even when other industry people discuss the game, its Eye-Ko. If you think about it, it has the same structure as the word Icon. Take the en sound away for the lack of an N, and you have Ico - eye-ko.
However granted, that the I sound in Japanese is often pronounced with an Ih sound, it might actually be Ih-ko.







