Is there any way to beat the giant chest that eats cards and spawns enemies? I keep getting rekt on that level :'(
Without giving it away, here's a hint: beat the boss with his own friends. It's a battle of attrition, but definitely winnable. Good luck :)
Once that boss is down and doesn't swallow cards anymore/doesn't produce new enemies, is the game over or do you have to do something else? I have seen no end sequence, but currently I can just beat that box or the rocks around it forever and nothing happens.