first of all , lol THIS IS A SPOLIER. And lol yes it is hard, actually what i did i put on god mode for the first time and got to the end and took it off pretty cool and they ARE insanely hard.
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"Does it really smell like cookies. Ohhhhh, she farted and it went down my throat." Guy from Family Guy
There may be what tortures you.
There may be what reduces you to silence.
There may be what fails to satisfy you.
There may be what irritates you.
There may be what grieves you.
But man has to train himself by enduring these things.
Are you talking about mission 5? That level is a bastard! Basically, duck a lot, use the red marks on the compass to find where the shots are coming from, and if you take too much damage before locating the enemy, quick load and then blow him away without taking any damge.
Sometimes enemies can be really high up in the air, or hard to see through tanslucent windows. Remember to scan for them both horizontally and vertically.