The default camera settings should be changed
Currently, the default values are:
cam_dist 160
cam_height 25
cam_speed 0.3
These default settings make it difficult to see what's in front of you, and can increase feelings of motion sickness due to the rapid scrolling of nearby floor textures. Additionally, the low cam_speed value makes mouse movements feel unresponsive. When moving backwards, the camera sometimes can't really keep up (for example, after bouncing off a boss with the thok). Personally, I'd reccomend these settings to be the default:
cam_dist 200
cam_height 55
cam_speed 0.6