The old palooka (and I do mean old) scored a more-than-respectable $6.2 million on opening day - a mid-week opener to boot. Seen on 2,752 screens, that's a per-screen average of $2,267. Whether the MGM release can last more than a few more rounds is up in the air, what with several big features opening Friday. They include "Night at the Museum," "We Are Marshall" and "The Good Shepard." But my money is still on Rocky, especially over the holiday weekend. The critics, meanwhile, seem almost embarrassed to give the film a good write-up, but somehow it scored 77 percent on Rotten Tomatoes (and 79 percent in the Cream of the Crop section). Terry Lawson in the Detroit Free Press speaks for a lot of the critics: "What sounds absurd in print - a 60-year-old Balboa gets back in the ring with the reigning heavyweight champ - is thoroughly, satisfyingly enjoyable on-screen."