When you pause a mission and continue afterward, 3 2 1 sequence will start then.
Considering that this game is a Shoot 'em up game (with Bullet hell maybe) I think its quite common to add the features to the game (not that its a insult or anything Dev).
A great way to prepare. Like a bunch of egg on your way, you paused it make a maneuver to dodge it instead of a instant continue, a sequence will start counting down to continue.
You can use the same CI5 UI to this as well putting a 3 then 2 then 1 then all three disappear as that.
Do you think this will add considering that the style of this game is like Space Invaders?