Each mission has several map variations, and enemy spawn patterns, so while you might play the same mission three or four times, you may not see the same exact map twice in that time. The developers have done a decent job of making environments with places to take cover, multiple paths to take, and even some environmental hazards to worry about. On one of my first missions the team cleared a room and were all standing in front of a corridor that I chose to dash into, thinking we were all moving on. Said corridor wound up being a ventilation shaft for the mining facility and my character was burned to a crisp when the burners came on.