Block Logic

I'm in the middle of making my logic game for cell phones. Hm, ok not middle,it's more like 70% of already made game. Animations of player, graphics, game logic - all of this is already made and working. I need to create some levels and I'm also thinking of random level generator. Hm do you think that sound is important in mobile games? Because until now, every game what I have made for cellphones was without sounds.. Should I work on some sounds for Block Logic or is it "not necessary luxury"?