Will I miss anything important if I turn the sound off?
Solution 1:
No. The only sound in the game is the music. If you turn the sound off, you'll miss nothing beside a guitar track by the creator of the game himself.
Solution 2:
Turning off the sound will affect something other than the music volume – it will skip running the sound code, giving somewhere between an infinitesimally small and a noticeably large speed boost depending on your system.
Of course, I know that's not what you meant to ask, but it is a pedantic answer to what you wrote. ;)