1. Enemies never run out of ammo. No matter how long did they shoot, their weapons always contain exactly the same amount of ammo when taken.
2. There are health items and ammo scattered on the floor so that the player can use them. Enemies will never use these items - a heavily wounded soldier will not have an idea of taking a nearby medikit and a pistol-using man won't take a flamethrower.
3. The player can carry lots of havy weapons, but he won't be slowed by them at all. Also, when loking at the player, one can't notice any weapons he's not using at the moment.
4. The player can survive 18 pistol shots at up close, but an armored soldier will die after being shot 2 or 3 times from a longer distance.
5. When an enemy dies, all his items you can take will immediately fall out of his corpse.
6. No matter what caused your wounds - being shot, burned by fire or being too long underwater - they always look the same and if something can heal your wounds, it's not important what exactly is their nature.
7. You can pick up items just by running over them, you don't even have to touch them with your hands.
8. When using ammo, your weapon refills automagically, you don't even have to put ammo into it. The same applies to health items, they will heal you in a nanosecond.
9. If you pick up a weapon you already have, you will take all ammo from it and put it into weapon you already have. An empty weapon will then disappear without a trace.

come on... REPLY! It seems you are speechless

10. You open doors without actually touching the door.

11: You can be hit in the throat with a dart gun but still explode when you die.

12. It doesn't hurt when you're hit in the crotch.

13. Cars that fall always explode.
14. You can still control your car while your going 100 mph down an icy road with enemy cars firing machine guns at you and ramming you
15. Cheat codes solve everything

16. The more patches you install, the more bugs pop up.
17. The mod is always better than the original.

18. You have all the weapons in the world, but suicide is not an option.

Yaniv- You can often jump from a high building and die;)

19. Where are my feet! were are my feet! You Look Down and got no feet but only your shadow
20. You Just Picked up a second pistol and can wield only one at the time.
21. in the rare times a heavy weapons slows you down it slows you down only when you select that weapon
22. You reload a new clip and trow away your old, yet the bullets in it are still in your stockpile
23. it takes you 8 seconds to fully fire 30 shot clip of a gun that has a rate of fire of 1200 rounds per minute
24. Weapons and goodies on the floor are unharmed by projectiles and explosions
25. All members of a type of enemy or creature looks exactly the same
26. Cant kick or pick up and trow back granades (maybe becouse of 19. ;) )
27. You can jump and crouch for hours with no consequences
28. You might have high exlosives and heavy weapons but you cant open a locked wooden door unless you got the proper key.
29. there an obstacle at waist height that you cant cross by jumping therefore you need to walk around it.
30. you partially hide behind an object and while your weapon is cleary next the object when you shoot you hit the obstacle very hard air next to the object.
31. you torch all kind of wooden stuff with your flametrower yet they never catch fire

32. None of them are half as fun as civilization! (not so much a glitch, just more of a downside)

33. The AI never shoots you while your humping/crouching over a corpse.