Note that enemies have the same range of vision on Hard and regular Extreme.

From right to left: Very Easy, Easy, Normal and Hard/Extreme.

The enemy range of vision is very long on E-Extreme.

From right to left: Very Easy, Easy, Normal, Hard/Extreme and E-Extreme.

• Enemies don't quit a hold up on their own from Very Easy to Normal. They do from Hard to European Extreme.
• Some cameras now rotate.
• On Extreme, the player cannot shoot the tarp or the lamp during the Olga fight.
• Strut B has cameras when it's entered after meeting Stillman.
• On Extreme, there are already ciphers on the EF connecting bridge when it's first entered.
• There's additional bomb on strut E on the conveyor. The room also contains extra cameras.
• Hard adds an additional bomb to strut D (sediment pool). Extreme adds two. The location varies on NG, NG+ and NG++.
• Fortune is much more aggressive on Extreme firing off two shots at a time.
• On Extreme, Fatman ambushes the player at his bombs much more actively.
• The president is sleeping and he has to be woken up with explosives.

• On Very Easy, the player doesn't have to log on to a node for the radar.
• Countdown timers vary by difficulty.
• The M9 can be obtained at strut A on Very Easy and Easy.
• Fatman sometimes drops Socom ammo when knocked down on easier difficulties.
• On Very Easy, the Shell 1 core caution ends after changing floors with the elevator.
• Guards don't come to check the situation after the Harrier fight on Very Easy.
• The Nikita is slightly easier to obtain on lower difficulties.
• The time Snake appears to help Raiden during the sniping section varies by difficulty.
• On easier difficulties, the floor boards on the EF connecting bridge respawn for when Shell 1 is re-entered.
• On Very Easy, the player gets full ammo before the Tengu 1 fight.
• The number of RAYs the player has to defeat varies by difficulty from as low as 3 to 20.
• Ranks and how to get them also vary by difficulty and very easy has no ultimate rank.
• The top ranks in the game by difficulty are Hound (Easy), Doberman (Normal), Fox (Hard) and Big Boss (Extreme)