I don't know how you could replicate it but parallax is giving me problems, random particles are bursting and the boss has made it slow down for some reason. Earlier in the game (cemetary) I was able to get past slippy by running past all of the enemies and have them pile up. I then jumped on top of them to skip that part. Also, when using checkpoints I noticed that everything was saved from that point on in the level. As long as I got to the checkpoint I could die as much as I wanted and have no consequences.