Two goals from Sam Baldock proved the difference between the two sides as the Seagulls moved to the top of the Championship table.
The centre-back however feels the result is not a fair reflection on the game and that on another day, the Reds could have taken something from the match.
He said: "It was very disappointing on our part, I think we played well and probably didn't take our chances and a team of their quality, they didn't have many chances but they took them, that's why they're up at that end of the table and we're very disappointed.
"It was little fine margins in the game, we know they're a solid team and as I've said, that's why they're up there. They don't give much away so when you get your chances, you have to take them and unfortunately we didn't.
"They've had two half chances and a bit of quality from them and we're 2-0 down. I don't think we deserve the result, it flatters them a little bit, but that's the end result and we're very disappointed because we thought we deserved more from the game.
"They've got some good players don't get me wrong but I don't think they troubled us that much, I think we stayed solid as a side, they never ripped us open I don't think, it was just two half-chances and that's where the quality does shine for them. It's just disappointing from our point of view."
Robbo' added that the squad will aim to take as much information as they can from this afternoon's fixture and apply into next weekend's clash with Huddersfield.
He hopes they can learn from their mistakes in this afternoon's match and wants them to continue to push hard between now and the end of the season in May.
"We've come very far as a team and we're not going to stop here, we're not in this league to make up the numbers, we want to keep getting better. We talk about it every day and we've shown Brighton, one of, if not the best team in the league, a good game. On another day, we might have got something from it.
"We're always trying to improve on the training pitch and the Gaffer has said we'll look at that and see how we can improve from that, but I think we've played well tonight.
"We'll look at every aspect of it to see how we can get better and get a win in the next game.It's another big game, they're all big but we have to move on quickly, get on the training pitch and work on bits and bats from this game and see how we can get better and get three points in that one."
The Reds are nine points adrift of the play-off places but the defender is optimistic that the side can still go on a run and continue to push towards the top six.
However, he was keen to stress than the focus of the side is firmly fixed on taking a positive result against the Terriers next Saturday.
"Now we've got this one out of the way, we'll look to the next one. If you do get on a run, you never know. We've got the quality for it, you saw what we did last year at a different level and why not, but we'll look first to the next game," added Roberts.
To watch the skipper's full interview on Barnsley Player HD, CLICK HERE!