Great followup, but too short!
The skill settings are also too tame. Usually "hard" means just that; hard! But in this instance I would personally rate the hard setting as simply normal. I'm going to play through once more on very hard just because it was over so quick, but I don't expect much more this time around.
Buggy AI:
Allows laser pointer to be permanently on, so if you're cloaking with a laser pointer you still can't be seen! Too easy!
Longer distance enemies seem to remain static which makes it far too easy to snipe, and then their local comrades don't react to them dying! Also enemies with rocket launchers or longer ranged weapons just don't use them! Maybe because their sight lines are too short, i.e. they only see you when you're 10 metres away.
Weapon / ammo stock piles are far too frequent even on hard (not sure if this makes a difference?) and overall it makes life too easy.
Nanosuit enemies are also too easy to kill, and bizarrely remain mostly static when engaged. They don't hunt you like in other games, and in warhead they never use speed or strength to flank you or throw things, so merely use cloak and armour with limited effectiveness.
Aliens seem slightly harder this time around, especially in groups, but again they don't react when others are engaged, which makes it again too easy.
Overall, I am slightly disappointed with the single player, and have yet to play the online multiplayer, so hopefully this will improve the longevity of this game.