Long, Grind-it-out game, help wanted

2...e6,3...Nf6,4...Ne5,5...Na5,6...Be7,10...O-O,19...Qf6,24...Qc7,27...b5,38..Qf1,43...Qb8+,are-all-improvements,but-44...Qb8+wins.
Discussing this interesting game with a friend, he found an interesting move. What is black's respone to 35. Qg4! It forces black to simplify which leads to a advantageous position for white.
Discussing this interesting game with a friend, he found an interesting move. What is black's respone to 35. Qg4! It forces black to simplify which leads to a advantageous position for white.
35Qg4!!-wins.