I just thought I'd add that I've been playing console games since the original Nintendo, and 'PC' style games since the Atari 512 (STE!). Never have I considered controls as anything less than the most important factor in enjoying a game. If you can't control something intuitively, or if some aspect prevents you from doing a legal in-game action, or if you get frustrated, then the controls are not good enough.
Ports from consoles have this as their number one problem. Look at Halo and Halo 2 - reasonably sub par shooters but consigned to the shit heap due to their god-awful controls. I almost cried when I played Halo 2 on a friend's Vista system after he bargain bin'd it, it was so bad.
Anyway, porting a console game to the PC and not taking the time to at least ensure the universal control method - mouse and keyboard - is up to scratch and responsive enough is tantamount to failure, from the perspective of experienced PC gamers at least. I consider myself in this category, I consider many others on this site similarly, and believe us when we say Dead Space got it wrong.