Me, playing solo and me playing with my GF co-op have consistently got to the valkyrie and got the boss to about a third of its health.
Each time we have done this the game crashes and/or we fall through the map.
Has anyone else experienced this. It ultimately means we cannot finish it and have to keep starting it from the beginning. There should be checkpoints. It wouldnt change the difficulty, would just make it more accessible given the constant crashes.