Game Physics

[Daemian]

I thought he meant when the object is glitched with another and it starts growing in speed and changing direction, like trying to get rid of it. Then it's shot away. xD (e.g. a chair stuck inside a fireplace) Isn't that optimization?

One rare glitch that I know is when you walk/run against a corner in Amnesia, for a short duration, and it lets you go through.
(e.g. the developer hid the door key somewhere and you don't want to look for it, you can run for a sec against the middle of two objects, like door frame and wall, and suddenly you go through.)

And here is the apjjm's speedrun abusing some glitches. Read description.