A trip to the shop before
selecting your level can help to push the boss battle odds slightly back in your favour, with health
upgrades, slow - mo regeneration
upgrades and plenty of
powerful weapons available to buy, but affording these will take finishing several levels to ensure you have enough coin to buy them, something which isn't a joyous task when you're breezing through the game's easy setting over and over just to get something
powerful enough to conquer the normal setting.