Alcohol is a depressent drug that when consumed slows down parts of the central nervous system including the brain stem and cerebellum. It is consumed primarily for its psychiatric effects (a.k.a the "drunk") on the consumer. NintendoCapriSun briefly referinces it a few times, including in his Super Mario Galaxy 2 lp in the beginning when he jokingly asked the luma that was asleep if he "got too drunk last night."