More bug fixes

Some people are still seeing the skipping bug, so over the weekend I made some changes that should help address it. If you're still seeing it (and you'll know if you see it) let me know.

I fixed some literal 'edge cases' where Nemo could get caught on corner collisions too. Unfortunately (or fortunately) this fixes some places where princess could get caught on corners and get to places she shouldn't be able to.

We also made some level changes to the Mushroom forest.

Thanks so much for all the feedback and notes! We're a very small team, but working hard to address everything we can!