Steam Works is not the first game to have this, Small Islands, Palaces of Carrara, Santorini all have similar timers on their End Turn button. I find that (in realtime games especially) it is easy to forget to press a confirmation button if you have taken all the active steps you intend to during a turn - especially since most games here don't have a confirmation step at all, although this is also not ideal since it means players are unable to Undo their very last click of a turn.

I'm aware this is a divisive feature and I ask for opinions to be directed to the forum thread at boardgamearena.com/forum/viewtopic.php?f=12&t=16770 so that it might be possible for form a consistent convention for new games.

This feature is now optional, defaulting to always waiting for confirmation.