Managed to get a "winning position" around move 21, but lost the advantage in the end.
I didn't go for 28... Bxg2, as I didn't see 29. ... Qe1!! after the recapture 29. Qxg2.
By the way, is 8. Ba4 a bad move for white? According to Stockfish it is -0.9. It seems quite bad compared to the other moves like Qf3 or Be2 or Bd3. However I don't know what is the key idea to punish it.