This is an adventurous shoot em up game where you have to do a lot of stuff, other than just shooting! You have to infiltrate into the enemy base and kill all the guards as you proceed further and finally defeat their boss.
You have to move from one room to another using keys and passwords, which you will find along the way. Look around and search for clues. Also collect the health packs and weapon upgrades as you find them. Hide behind walls to avoid getting hit, Good Luck...

Aim - Mouse.
Shoot - Left Click.
Hide/Come Out - Space Bar.