The game will ask for your age. It must be between 18 and 99, inclusive, for you to be granted access to the game. Of course, nothing keeps you from lying... ;)
On the PC, the age verification questions (which can be surprisingly hard for people who are old enough nowadays) can be bypassed by pressing Alt-X after you have entered your age. We won't list the questions and answers here because the list would be too damn long (there are over 150)!
This walkthrough will give you the maximum number of points.
Enter the bar, sit down, and order some whiskey. You pay for it automatically. Now walk to the hallway, get the rose from the table, and give the whiskey to the drunk. (If you walk too close to him, you'll kick him in the balls!) Now go to the bathroom -- both in the sense of entering the room, and sitting on the toilet. Stand, but do not flush or you will die. You can wash your hands, but it's not necessary (apparently, you don't have to be hygienic in computer games). Keep reading the walls until you learn the "Ken Sent Me" password. (Inside joke: "Ken" almost certainly refers to Sierra employee Ken Thompson.) Take a ring that is hidden in the sink.