You might consider applying the user pain metric to your bugs and only dealing with the ones that are a serious usability concern. Hopefully if you've structured your code well you will only have to consider smaller sections at a time rather than hunting around the entire code-base.
Unfortunately if you've gotten to a near complete state and allowed bugs to remain in the software till this point, you will have a lot of code to go through. It's often easier to ensure you're properly testing your code during development and try to deal with the majority of problems as they arise; you could perhaps even use TDD.
It's up to you really... if you want to finish the game, you need to put in the work to do so. If not, you could perhaps try to take a better approach your next project so that you experience less problems, but again at some point you will inevitably end up with some work (often debugging, documentation, or adding final usability features) you don't really want to do -- if finishing a game is important to you, you'll need to such it up and do the work.
Does that help at all?
: Fixed link.