3D level design where you can get stuck on elements when you just want to move past them. Especially frustrating in racing games or sections where you have to move fast. Controls are just not precise enough to deal with this under stress.
Visible polygons and interactable polygons are not the same thing. Play Banjo Kazooie and Yookah Laylee (including the remake) to see the difference. The latter has you constantly bump into things because the environment is not smoothed out.
On the other hand some studios take it to the other extreme and make you walk almost on rails, childproofing every corner. A good middle ground is needed.





For the dead person it doesn’t matter but for anyone else it’s better to put the rotting body where it doesn’t stink up the place.