I was so pleased to see this game show up on GoG a while ago that I bought it instantly. However I stopped playing it rather quickly because the game doesn't capture the mouse to 1 monitor, so anytime I try to edge pan it just goes to my other monitor. Is there a fix for this, third party or otherwise? I'd really like to sit and play this game again on my upcoming weeks off from work.

Try to make as
http://savepic.ru/4015876.jpg

Right, of course that might be the problem lol. I had to turn that off because when it's on it really screws with my mouse. Sensitivity goes to complete shit, and if I start turning up the sensitivity the cursor starts going all wonky. It gets very delayed and moves around weirdly

So that, you help it?

Well Direct Input locks the mouse to the game, but the mouse sensitivity for the game (while Direct Input is enabled) is very poor. It's laggy and inaccurate.

Maybe for your mouse must install the driver for its normal operation.