I've just released a Countdown Watch that allows to set a maximum mission time. In game, it replaces the standard watch and lets the players see how much time they have left. Optionally, an End Game can be triggered when the time is up.
It is also possible to set your custom watch faces by specifying a different image to use with the watch. To do so, you will have to create a watch face with the same dimensions of the included one.
It can be found here:
We use this watch in the internal missions we design with 2RGT (check us here
if you are looking for an Italian clan).
Comment and feedback always welcome.