I don't like that this is character exclusive. I went through all the trouble of getting every chaos emerald as every character, and only one of them gets to go to Final Brak. If this level is meant to give a reason for collecting all the emeralds, that should apply to everyone, not just Sonic.
Overall, it's a fine enough level, but it doesn't really feel as climactic as it should. The meteors feel less like an obstacle and more like a roadblock, put there to annoy you. Brak himself doesn't really do anything a bossfight should, he can't attack back and doesn't feel threatening. As for the "arena" itself... it's just open space. No Egg Rock ruins, no approaching the planet's atmosphere, just... space. It feels like something's missing.
There's potential here, but it's not as refined or impressive as it wants to be.