To reach 300,000 points use a second control. Add coins with
. When you start the fight press
on the second control. Each fight you win 20,000 points to finish, plus additional points for punch. Continue this process until you reach 100,000 points, go back to the normal fight. then save the game and exit the game. Reenter the game, then the first achievement of 100,000 pop-up. Do the same process for 200,000 and 300,000. Hope this helps. Good luck!