COLONIE — The Regal Entertainment Group used the movie “Atonement” to publicly christen its new 13-screen theater at the Colonie Center.

Almost 30 months after construction started on the Colonie mall’s third-floor Regal Cinemas, movies started playing there Monday afternoon. In the run-up to the theater’s grand opening Friday, the Knoxville, Tenn.-based Regal is showing second-run films. The Academy Award-nominated “Atonement,” starring Keira Knightley and James McAvoy, was the theater’s first scheduled film at 12:10 p.m.

Other films slated to show through Wednesday include “10,000 B.C.,” “I Am Legend,” “National Treasure 2” “Sweeney Todd,” and “Enchanted.”

For each day during the three-day soft opening, Regal will also show a trio of films revolving around themes. They include “Spider-Man 3” for Superheroes for a Cause today and “Water Horse” for Family Day at Regal on Wednesday.

The theater is charging $2 for tickets, popcorn and soft drinks through Wednesday. Proceeds from the soft opening will go to local charities.

The 2,800-seat theater covers 64,000 square feet. It features digital projection and stadium seating. First-run films, such as “Chronicles of Narnia: Prince Caspian,” start at the theater Friday.