Barkley had 10 rushes for 26 yards and one catch for 1 yard in 28 total snaps 11-plus months after suffering the injury. His longest gain went for 5 yards.
Barkley said he "felt pretty good" getting tackled and playing in a game environment for the first time since Week 2 of last season.
"Nothing alarmed me. I guess you can say that is a positive sign," Barkley said.
Just playing football again was an accomplishment.
"I was more nervous early in the week when the conversations started happening," he said. "When I woke up today, I had no nerves. At the end of the day, it's football. If anything, it was more excitement, just happy to be back out there.
"I know I put a lot of hard work -- blood, sweat and tears -- just to get to this moment and come out healthy out of this game. It happened. Hit that milestone. I was happy I was able to play in Week 1. That was a goal of mine, to get out there and help my team win. Now it's actually getting out there and helping my team win."
The next obstacle is a quick turnaround to navigate. The Giants play Thursday night at the Washington Football Team.
Barkley wouldn't go as far as declaring himself ready to play again in four days. This isn't an ideal situation for a player coming off such a serious injury who was eased into the action Sunday.
"Right now I'm going to go home and see how my knee responds," Barkley said. "Take it day by day."
Barkley wasn't officially medically cleared for the contest until late in the week. He didn't participate in a padded practice that involved any contact until the previous week. So he was up against the clock to be ready for the opener.
It didn't take long for the Giants to get Barkley involved. He ran the ball for 5 yards on the game's first offensive play, much to the delight of the home fans who didn't have much to cheer about afterward, as the Giants lost their opener for a fifth straight year.
Still, coach Joe Judge said he thought Barkley moved well. There just weren't a lot of holes or open space for him to operate.
His teammates also thought his return went well.
"I mean, coming off an injury like that, a lot of the stuff is mental," said wide receiver Sterling Shepard, who was the Giants' most effective offensive weapon with seven catches for 113 yards and a touchdown. "I didn't sense he had any mental stuff going on. I felt he hit the hole hard, took some hits. That is what I wanted to see, to be able to bounce back up and keep on pushing."
And they expect the improvement will continue on a weekly basis.
"He'll gradually keep getting better and better," Shepard said. "That is his first time out there in a long time. So I'm just proud to see him out there and happy to be out there playing with him again."