I wouldn't mind seeing ASE locked doors go away, there's really no need for an extra button press just to open doors. Also the glitches, bugs, crashes and the like. I'd also like to see the credit system reworked for single player. Have a point system for every level. If you don't get hit, bonus credits, if you don't die, kill X amount of enemies in a row, only use a certain gun, all for specific bonuses. More reasons to keep playing single player.