Just cruising about on ModDB when I realised I had some alerts, checked them and it turns out the good people working on the Resident Evil: Twilight mod have released a patch allowing you to use your mouse in Resident Evil 4.
Hope someone finds this of use!
This patch adds a mouse support option to Resident Evil 4. So you can play the game with the shooter-typical combination of mouse and keyboard.
Hope someone finds this of use!

