Ack, I was pretty proud of my collision systems - for the protagonist, at least.
What's bizarre about them? You generally keep moving towards the point of view, so obviously if you bump into a corner you won't get anywhere. Also, the lanterns have a circular collision box larger than their actual size, so they may feel a bit weird.
As for the camera movement - get the width/height of the screen, calculate the distance between the centre and the mouse position, change direction appropriately, set the mouse point closer towards the new point of view. This causes a decreasing 'delay' in stopping the mouse movement, but also has some downsides, ie. when you try looking infinitely high/down, or in that you can't really get the mouse cursor outside in the game window (when eg. another window appears over the game).
starsrift: Thanks. It was a bit experimental (like the game itself)