0-8-6c contains several bugfixes, including a game-breaking one that would happen when you defeated Karen.

There are also some changes to the flashlight's lighting, the darkness tint is lighter so that you can see your character, and a couple of new weapons — the brick, water gun, and crystal chain — are now available to be found.

Of course, all of this builds upon the new stuff added in 0.8.6. Read all the changes in this major update here.