Every enemy you face in crysis2 has a weakness if not several. Time to Break some of them down.
Spec0ps Grunt: Cell Mercenaries - These guys are not very bright even on Post-Human Warrior. Using Stealth out flanking and using C4 at tactical locations helps 100% of the time. Then again Gung-Ho is usually more fun.
Spec0ps Grunt 50cal Gunners - These guys can be very dangerous and just as intimidating the first go around, take advantage of their blind spot. Out Flank them, either get them from ranged and re-cloak or sneak up behind them with a silenced pistol while cloaked and put 1shot in their head.
Ceph Grunt - Its ok to be cautions or edgy the first time you seen one. Use Heavy Cover and leaning, Stealth kill from the rear or stay at range. Remember if you come under fire by one or more Armor Mode will save you.
Ceph Stalker aka Reapers - These Ceph are far more aggressive maintain cover where possible and stay at range at all times. Bursts shot until close distance spray and pray and melee range. Stealth Isnt an Option.
Ceph Grunt Commander - Similar to the Grunt's but heavier armor and a bit more firepower. Aim For the Head Burst shots with Assualt Rifle. Z-volt gun highly effective.
*Ceph Heavy - Missile Launcher and Assualt Weaponry implanted on both arms use extreme caution. Do Not Approach, keep at range where possible, 2xC4, 3-4 Rockets, 2-5 L-Tag's all are highly effective. In a Pinch? Z-volt until shield is fully Depleted immediately switch to under-barrel grenade launcher one shot does the trick 90% of the time. When all else Fails Armor Up and Mk-60 or HMG until splatter and sauce.
*Ceph Tri-pod Aka Pinger - Heavy armor on 60% of surface! Flank, Fire, Cloak, Flank, Weakness in its rear. Use Heavy Ordnance. HMG N/A.
*Ceph Gunship - HMG (pref Mounted) or Rockets. Stay Cloaked till In-position and Ready, Armor mode before firing.
*Deflection where possible
Mixed Tactics - The Nano Suit is best used for hit and run. Do alot very fast, Cover recharge cloak and move to a different spot. Avoid getting pinned down in one position, feel free to run and fight another day. This idea of tactic is highly useful with numerous enemies. Remember its not cowardly its tactical.
Plan A-Head - Use the visor to your advantage pre-mark all ammo boxes and resupply locations as well as any items of interest.
Over Watch The Observer - Prudence is in the planing, even if you want to Gung-Ho Chuck Norris the entire game. C4 Det packs and Stealth kills at secluded locations keep you and the kill out of sight and out of mind. Watch the movements they all have patrol's and rounds to make. Use that.