If you use the effect command to use speed 10 and slowness 127 together, your view flips and all movement is reversed. (i.e. moving forward moves you backwards, moving left moves you right, etc.)
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The correct thing is to fix this, and add another effect that does the "awesome" thing.
I guess. Found out that the moving thing only happens at slowness 6+. The view inverts at 23.
Also of note is that Speed 128+ messes up the screen in different ways. It seems to vary between inverted movement and upside down screen.
Maybe rename this something along the lines of "Uncaped Speed/Slowness Potions Break Camera"?
No! Please don't remove this! It's true but it's soooo awesome! Well, the movement's a little weird but the view is amazing!