So i was playing clive barker undying and my mouse was weird if i'm moving the mouse suddenly moves to one direction like a flick or a big acceleration, that happens on soldier fortune as well, quake 2, daikatana and so on...

Idk if this is the mouse acceleration problem, but it's annoying and the and i already tried to install MARKC Mouse acceleration fix but idk if i installed wrong or did something wrong, but it dind't work it.

My mouse is a G502 Wireless if this matter anything.

Maybe try this: enabling DirectInput in System.ini

(from https://www.gog.com/forum/clive_barkers_undying/unplayable_due_to_mouse_acceleration )