Gameplay is turn-based so you can plan what you want to do calmly, but results are fairly immediate--if you miscalculate a move your soldiers get hurt or die.
You have to take risks: you must move your team of soldiers ahead into the darkness to accomplish a mission, but there could be aliens around the corner waiting to ambush them.
You can take a risk and have a soldier move ahead to grab some loot (meld) which can grant huge bonuses, but it could expose them to danger. You must decide what they will do.