What is the name of this PC video game?

So here are the details i remember about this particular game-

1. It is entirely an FPS like half-life.

2. The player assumes role of a male

3. Player receives and can carry multiple guns at a time.

4. In a cut scene, player can listen to two scientists talking about a new gun they made. But one of them keeps the trigger on for too long to charge it and they both die.

5. Because of this explosion the wall breaks and player can use this gun now. Its power is very much similar to the alt-fire of combine gun from Half-life 2.

6. In the same sequence, the player needs to set 3 laser lights placed with mirrors in 3 different rooms.

7. The roof ha 3 transparent tubes/pipes which start glowing once the related laser light is switched on.

8. The game is available on PC.

Thanks...