Vincent, the protagonist in Catherine, hangs out at a bar called the Stray Sheep. It’s the only place he can unwind. While you’re hanging out with your buddies, you can order drinks. According to this screenshot, there are four types: whisky, beer, sake, and cocktail.
The meter in the bottom left shows how much alcohol is in Vincent. Drink too much and you’ll stagger on your way home.
But, those drinks give Vincent an advantage in Catherine’s action part. Drinking makes Vincent more agile during his nightmares.
Officially, Atlus still hasn’t outlined Catherine’s gameplay. Leaks from retailers and an achievement list peg Catherine as an action puzzle game where Vincent scales a tower to escape from a monster below.