Dead Spaces's physics is tied to to the frame rate. This includes the controls as well. At higher framerates not only does the game become harder to control but other things can break as well. I found out about it from this video https://youtu.be/R8ue7RnUdd4?t=54 I tested this myself and can conform that I too had the same experience and was able to fix it the same way. Since I found this information to be useful I thought I'd posted here as well. Hope this fixes any issues you may have experiences.

Link to the mouse fix: https://community.pcgamingwiki.com/files/file/840-dead-space-mouse-fix/

Also apparently the difficulty mode has a habit of changing https://pcgamingwiki.com/wiki/Dead_Space#Difficulty_changes_itself_when_multiple_save_files_are_present

This Fix makes my game (newest gog) crash ion saving. ON SAVING. In a game without checkpoints. This might be the worst possible bug.

ò.ó