Adjusted 2P hammer position to be 1 pixel away from 1P hammer - so there is no advantage.
Synchronise the on-screen bonus timer with player 2.  This ensures the correct bonus score is awarded to P2.
Use sprite address 0x6a70 for P2 Jumpman instead of 0x6930.  This ensures Jumpman appears in front of the retracting ladders.
Adjusted score sprite colour for player 2.
Relocate P1 and P2 to top of rivet stage on completion of level.