RNG hell
It's good if you want more Inscryption. The card game mechanics are fun but honestly this extra mode is disappointing.

I expected more for an endless mode, like instead of deleting many items and puzzles from act 1, it could have added more to do on the cabin. You just unlock 3 unique items and that's it.
There's only one new event (the card painting one) and you unlock a small selection of cards by completing the challenge requirements.

I wanted more
More stuff from the other acts, like bosses, cards, mechanics.

Thanks to the rebalance It's more like a less fun version of act 1.
It's very frustrating and you just pray to RNGjesus that the game throws you a bone... then you proceed to exploit a busted synergy thanks to a totem, or the black goat, or the mantis god, or the dire wolf. The goal is to find a broken combination using what the game throws at you, but it's very easy to stomp Leshy once the ball gets rolling. Good luck with that though, because the higher the challenge level is, the more frequent your defeat at the hands of bullshit will be.