I am back. I did play it with two players and recommend it that way. I played with two different people and the one that's usually bad at games picked it up faster so I don't know what you did but good job. Even if the other player was the one I got the furthest with. Over the hour combined I played with both of them, we did beat the boss once and it was by finding the room and re-entering it with full health by using the gate. We tried the hardcore mode but we couldn't do it. They both agreed that the spiders were op xD. But they were much more manageable with two people. It still felt like there was too much damage and not enough healing though. You have to get lucky with minimal spiders to have a good run. It was a while ago so I don't have a ton of details, but it was significantly more fun. I know it is a demo, the only new thing I have the upgrades from sensei guy don't reset for the second player, they just stay. Which is good for grinding, but not great for playing with new players. Oh and sometimes when you get webbed and use the dash attack you still can't move until the web disappears.
We had a small problem with lag again, but I honestly think it's my pc, no idea what it is but game pretty much runs smoothly. Still checking for updates, can't wait for the epicness that follows.