Judging by the players’ reactions to the debut of the BIG3 three-on-three basketball league Sunday at Barclays Center, Ice Cube’s project is off to a fine start.

“It was great,” said Mike Bibby, former Knicks point guard and captain of Ghost Ballers. “I didn’t know what to expect coming into the gym. It was great and the teams loved it.”

All eight BIG3 teams were in action for Sunday’s quadruple-header. Each of the 40 players is an NBA veteran, with some former All-Stars and one Hall of Famer: Allen Iverson. Games are played to 60 points on a half court that added more intimacy than the full-court NBA.

It was also more physical than today’s NBA. Both Corey Maggette and Jason Williams, who each played at least 12 NBA seasons, left their respective games after suffering knee injuries, while everyone else fought through rust and each other.

“It’s just very competitive,” said Cuttino Mobley, who retired from the NBA in 2008 due to a heart condition and is co-captain of BIG3 squad Power.

“It was definitely more physical than we thought,” said Kwame Brown, the former top overall NBA pick who plays for the 3-Headed Monsters.

The first two games came down to the final shot as Rashard Lewis, a two-time NBA All-Star, and DeShawn Stevenson, a 13-year NBA vet, each hit game-winning 3s to win the game for the 3-Headed Monsters and Power, respectively.

Lewis and Bibby were also the first two players to score from the 4-point spot, which is just outside of the 3-point arc.

“You’ve just got to put a little more into it,” Bibby said of scoring from the 4. “It’s as far as it looks when you get out there.”

But all eyes were on Iverson, the 3’s Company captain and player-coach who played in the third game. He scored just two points on 1-for-6 shooting in the few minutes he played. However, he’s wasn’t as worried about the lack of minutes or the statline.

“I’m just happy that I was fortunate and honored enough to be one of the first guys to participate,” Iverson said. “... The best part about this game here tonight, and all the other games, it was exciting all around. It didn’t need Allen Iverson the player.”