It was great for nostaglia seeing Brock in full 3D with the original battle and gym not in black and white with primitive 2D graphics. He looks a lot more like he did in the anime here.
But since the game is a remake for the most part, the gym is about the same. He just has two underlings who are easy enough to topple.
I was worried my Eevee would be weak against the rock type Pokemon but geodude was easy enough to defeat.
And even Onix fell to just my Eevee. I remember in Pokemon Yellow, it was a nightmare trying to get Brock defeated as there are just normal type pokemon and Pikachu on your team.
And with his defeat you get the Boulder Badge and you get to move on to something better.