Do a few runs on easy to unlock everything, including the circular saw which will be a big help on madhouse. That means you're going to have to collect everything, heal no more than 3 times, open the item box no more than 3 times, and a less than 4 hours speed run. You can do this over several runs but you can also complete a few of these tasks in one run. After this, you should have enough useful items to get you through madhouse.