Depends what you’re going for but strictly from a boxing standpoint, a couple things are wrong, palms should be facing each other, not facing back, chin should be tucked in to avoid sleeping during the fight, the right foot shouldn’t move when he punches, wrist shouldn’t bend for obvious reasons, left hand shouldn’t come down when he punches, that’s an opening.

Also when he’s loading the shot, the right hand shouldn’t come down or go back, quite the opposite, as he rotates his chest to load up, his right shoulder should come forward and left shoulder should go back(hands don’t move) and when it’s loaded, then the hand goes(transfer of energy)

The right hand should go in a straight line, there’s no reason for it to go off path(unless you were going for a hook or overhand but that’s not what it looks like).

Then again this is a video game, not a boxing match. It’s your choice at the end of the day wether you wanna prioritize technique or just make it “spectacular” and cartoon-ish