Have You Played? is an endless stream of game recommendations. One a day, every day of the year, perhaps for all time.
I don't know when I'll ever get another first-person experience like SWAT 4, but Door Kickers [official site] is pretty close. It's played from above, but you command a squad of well-trained soldiers to breach and clear rooms full of criminals, and it's every bit as smart, tactical and exciting as its inspirations.
It can feel like a puzzle game at times: do you leave a man to watch this corridor, or do you take him with you because you're stronger when your squad sticks together? Do you take smoke grenades to block off that angle, or do you leave it clear so your off-screen sniper can take a shot? You'll die and die and try again, but the game becomes more compelling the harder it becomes. There's slight randomisation to enemy movements and starting positions too, which means it's never a simple case of rote learning. You need tactics if you're to survive.
Since release, developers KillHouse Games have continued to update it with new maps on which to play, but the initial offering was hardly small. If you yearn for a tactics game you can play in a lunch break and have fun with, then here it is.