SpecialForces74, there is a specific pattern you have to shoot the enemies. Looks at where each is positioned, and try to judge whether or not they would see you shoot an enemy.
jasondeegan, that's the whole point. That very first level is a rite of passage, and it teaches you about the enemy firing patterns and where they'll shoot next. That very first level teaches you more than a plain old tutorial. Unlike the other levels, you don't have cover. It trains you in your bullet dodging abilities. If you can't get through it, or simply prefer a tutorial with boring "Press A to jump" or "Kill this enemy standing still, because you're probably too stupid to know that right click is how to fire your weapon," then I suppose this isn't for you. However, that doesn't warrant giving the entire game a low score. Once you know the controls (which are very, very simple), the game is really fun. I dunno. I just prefer looking at the whole picture, not the first thing I see.