I don't know if you've been spoiled for it already or not, but I'll just say: the game is more than just collecting cubes. Well, it's still collecting cubes, but when you discover what it was that probably made Fish snap, cubes become kind of trivial.
It's not the best game ever made, but the music is amazing, the pixel art is gorgeous, and if you really push for the full experience (and get there by yourself), it's one of the most rewarding experiences ever.