SFJake: No way, thats really horrible. I need mouse and mouse views for anything and everything, and thats how I've always played everything. Its worse to me than playing a modern shooter with a 360 controller. Its not fun if you don't feel in control.
VSync, on or off, it doesn't change the mouse.
Ok I understand where you are coming from; but this does assume something the game _does not have_ : actual up/down angles. The Build engine games do not take into account Y or Z axis; only X. So your mouse is actually detracting from the game.
Yes, you've always done it this way because everyone, post-build-engine, built more possibilities in with enemies that could be on other levels. This is an _old_ game (: It didn't have that (:
Yes, the game _appears_ to have other levels (up / down angles, etc.) It's cleverly faked. There's a bit of coverage on the net about how they did it (or there was at one time; it may require digging thru the wayback machine at archive.org.)
Anyway, point is: the mouse isn't part of the gameplay. It's "bolted on" and will _always_ feel bolted on. In order to get it to act like you want, you're going to have to basically disable your mouse. It seems very, very wrong to do this, but basically set the mouse settings to completely useless settings for other games - VERY EXTREME up/down (maybe even "don't move up/down" ) and very, very little mouse response in the left/right domain.
You may have to alter the source and recompile to do this.
It is easier to just not touch the mouse, though it doesn't really seem RIGHT to do so (: