Factorio Forums

Using the OSX Command key in combination with W,A,S,D makes said movement sticky. For example, Command-S 'toggles' on movement south until the S key is pressed again.

Steps:
New game, get to where player is in control of character
Verify WASD movement working as expected
Press key combination Command-S
>Character continues running south after key release
Tap S key again to make the character stop running

The easiest way to see this is with player movement, as other keys don;t really care about stickiness. Works with combinations of keys - ie travel NE by Command-W-D. Each cardinal direction is toggled back off by press of corresponding key.

This is a problem inside OS X itself, when you press the Command key, it starts consuming all the key up events and doesn't send any to the application. It's not a Factorio issue, it can be observed here, in a browser: http://codepen.io/alexduloz/pen/nteqG