I thought I was 90% finished, but from just recently looking at all the stuff that still needs to be done, I'm only 70% finished. Here's an overall completion of things:
Coding: 90%
Graphics: 90%
Sounds: 20%
Levels: 50%
Overall Completion: +- 70%
Everything is still going along fine, I've recently finished with the graphics for all the ceiling and floor textures, the first lot I made were terrible, and then I've fineshed with the coding of the sprites (There are over 200 different sprites).