- Arkham City is four or five times larger than Arkham Asylum.
- The game starts by being briefed by Alfred, he explains the Two-Face vs Catwoman situation and you start heading to the area where the two are located.
- Batman is now much more agile, he is now able to plunge into a dive mid glide to accelerate flight.
- Two-Face has a gang roaming Arkham City, you will find them wearing face masks replicating their boss'.
- Criminals who aren't connected with any super villains roam the street.
- Story suggests that Professor Strange has been kidnapping Gotham citizens who are opposed to Arkham City.
- One and half years after the original game.
- Use new detective mode to discover a thugs super villain boss. This will be used to find The Riddlers men.
- The Riddler is in Arkham City, they hint you are almost certain to come face to face with him.
- Jack Ryder has been put into Arkham City due to him becoming to close to the truth on the city while working on an expose. Rocksteady were hesitant to reveal what Ryder had uncovered.
- Your first meeting with Two-Face is early on in the game. You are greeted with him displaying Catwoman tied up side down to a baying crowd of criminals. His two conflicting personalities being voiced out loud.
- Two-Face decides Catwoman's fate with the iconic coin toss. She gets lucky this time.
- The first confrontation with Two-Face results in Batman getting shot in the chest only for Catwoman to slip out of her chains and hit Two-Face into the acid she was about to be chucked into. A flirtatious conversation is then held between Catwoman and Batman only to be interrupted by a smiley face sniper dot rolling up Catwoman's suit. The shot is fired and misses her by a whisker.
- Your first detective mode experience is finding the bullet hole on the floor and figuring out its trajectory.
- Trajectory reveals the location of the shot. A bell tower housed by the Joker.
- Joker has a potentially fatal desease.
- Calendar Man is confirmed.
- The date and time effect your interaction with Calendar Man, set your console of PC's time a month ahead from last and you will receive a completely different conversation.
- Batman's launcher has received an upgrade, you can now stop at anytime instead of being forced to the end every time.
- You are pitted against a lot more thugs at once compared to the original game.
- Increased amount of combat animations.
- Phone booths ring only for thugs to stand by it, afraid to answer. Rumours going round suggest anyone that answers these calls end up dead.
- The mysterious caller ends up being Victor Zsasz, this starts one of many side quests in the game.
- To start the side quest you must follow a number of ringing phone boxes only to greeted with him at the final one.
- Co-Op seems to be hinted. Catwoman has very similar combat techniques to Batman when in game.
- Rocksteady suggest Crime Alley will make an appearance.
- Rocksteady insist that the only confirmed villains so far are the ones you have seen.

New Features:
- Added AI Custom Options menu to allow fine control of each AI's Core Strategy, Build Speed, Resource Income, Veterancy, Intel, and Target preference.
- The pre-order maps Emerald Crater, Iskellian Coast, QAI Prototype Facility, Seraphim VII Site, and Weddell Isle are now available to play for all players.
- Added a Cybran Mass Convertor structure, unlocked via the research tree.
- Added “No Artillery Structures” to game exclusions list.
- Added "No Mass Conversion" to game exclusions list.
- Added shield range ring indicators both during placement and on mouse-over.
- Added factional shield coloring, and quicker impact effects to improve overall visibility and feedback.
- Added a keybind to turn the UI and all associated in-game clutter on and off for screenshots and movies: Ctrl-U.
- Updated the current ranked season to season 2.

Balance:
- Increased Mass Convert cost to 2500e and income to 250m.
- Increased Mass Convert cooldown to 10 seconds.
- Killing enemy units will now generate 25% less Research.
- Illuminate Rogue Nanites heal decreased to 5,000. Was 10,000.
- Illuminate ACU Shield health decreased to 12,000. Was 15,000.
- Illuminate ACU Teleport, Damage, Rogue Nanites and Personal Shield upgrades each increased by 1 RP.
- Illuminate Rogue Nanite's range increased from 10 to 15.
- Cybran Battleship range decreased to 90. Was 115.
- Cybran Kraken health and damage increased by 50%. Weapons no longer prefer unique targets.
- AI veterancy cheat buff is now an increased vet rate, rather than free levels.
- Illuminate Point Defense cost increased to 200m/440e. Was 190m/420e.
- UEF P-Shield health increased to 600. Was 400.
- Nuke cost increased to 1000m/4000e for each projectile. Was 750m/3000e.
- Mobile units that are hunkered will no longer be affected by the magnetron.

Fixes:
- Fix for being able to assist an engineer assisting a factory and bypassing the build speed reduction.
- Fix for being able to have UEF Pgens assist an engineer assisting a factory and bypassing the build speed reduction.
- Fix for being able to have UEF Pgens assist an engineer assisting a factory and bypassing the range check.
- Fix for AI not sending early attacks.
- Fix for Air units not accepting multiple destruction part meshes in their blueprints.
- Fix for AI ACU going back and forth when there are enemies nearby.
- Fix for AI not using the Noah Unit Cannon.
- Fix for units getting strung out along cliffs.
- Fix for units that have queued move orders pathing weird after using an ability.
- Fix for beam weapons not turning off when units were loaded onto transports.
- Fix for Hover units not triggering properly when killed.
- Fix for UEF Long Range Artillery not being able to fire at their upgraded max range.
- Fixed Sonar Radius buffs to work like Intel Radius buffs.
- Units that are dropped from a transport will no longer infinitely loop their move ambient sound.
- Fix for AI units trying to climb hills.
- Fix for UI-based ACU duplication exploits.
- Fix for replay files not closing properly under rare circumstances.
- Fix for Platoon position being on unpathable terrain and screwing everything up for the AI.
- Fix for units being teleported when dropped from a transport over invalid terrain.
- Fix for the wrong leader being selected for Air units.
- Fix for GPNav group leader selection. Agents are eligible to be the group leader only if they are close enough.
- Fix for units that have queued move orders pathing weird after using an ability.
- Fixed resources getting refunded for units that have completed building and are cancelled with the stop command.
- Fix for units getting stuck against walls if they started out moving via steering only (no flow field).
- Fix for naval units not receiving commands outside the playable rectangle.
- Fix for some air units in a group slowing way down.
- Fix for crash when issuing guard on the ground.
- Fixed a version number crash when loading a saved skirmish game.
- Fix for crash when loading a save game while a unit is jumping.
- You can no longer send air units through an enemy Space temple beacon.

Improvements:
- When we buff a unit's max health we now set the units health percentage to the same as it was before the buff was applied.
- Removed the visual effect on other units from the Bodaboom and Universal Colossus to improve performance.
- Increased Bodaboom buff check time to 8 seconds and Universal Colossus to 6 seconds to improve performance.
- Changed the Bodaboom range circle to match the Bodaboom's buff range.
- Attempting to join a game when you have modified files and the host does not (or vice-versa) will fail with a warning message. This is true for joining through the game browser or by receiving an invite.
- We now disable collisions on units while they are in a transport.
- All Air to Ground and Ground to Air projectiles will no longer collide with each other.
- Units that die while jump jetting will fall like air units.
- Anti-Nukes will now show the proper Available/Max numbers when you hover over the build AntiNuke button.
- Made path requests NOT immediately reset from cost stamp collisions.
- If you lose and have a human ally that is still alive, you can no longer hear sounds from enemies under the Fog of War and can no longer see decals created under the Fog of War.
- We no longer remove units from their group when issuing ability commands (except in special cases).
- GPNav now allocates all the memory it will require for Integration Fields at the start of the game to improve performance.
- Jump jetting units will now adjust their flying height to avoid colliding with terrain.
- Reduced the effect ambient sounds have on the game's framerate.
- Improved 'should dodge' logic so if your push class is less than, then you should dodge.
- Improved 'pass through walls' handling so battleships don't get pushed onto the shore.
- If a unit cannot move as fast as the group, then the unit's speed bonus max is 15% instead of 50%.
- Fixed air units group speed calc, so its not just the leader speed.. its the speed vote, just like land units.
- Illuminate Flare effect updated. Now less expensive, added an on ground impact effect.
- UEF Disruptor Station Activation Effects. Bigger for better player feedback.
- Illuminate Electroshock beam and impact adjustments.
- Illuminate Radar Overdrive, added activation effect.
- All faction scaffolding effect LOD adjustments. Better player feedback at further LOD range.
- Tri-armor buff effect. Now better looking and less expensive.
- Reclaim, Capture, Repair, Build effect LOD adjustment. Better player feedback at further LOD range.
- All Faction Unit destroy LOD adjustments. Better player feedback at further LOD range.
- Experimental Unit weapon effect LOD adjustments. Better player feedback at further LOD range.
- LOD update on unit upgrade, build bonus, overcharge, mass convert and hunker. Better player feedback at further LOD range.
- Changed text for shield restrictions to imply structures only.

AI:
- AI will now use path markers for attack and scouting.
- AI will build additional radar away from its base.
- Magnetron will now look for targets in a radius around itself, rather than the base it is assigned to.
- AI will now build the Cybran Mass Convertor.
- AI will build more than 1 mass convertor, if needed.
- AI will now prioritize getting the Mass Convertor research if it has a high amount of energy stored.
- AI will no longer mass convert when it has enough mass already.
- AI will now build more Pgens when Mass Convertor is researched, rather than waiting for it to be built.
- AI will use the buffer size to check for blocking terrain (via GPNav) before building a structure.
- AI will try not to nuke its own units.
- Improved AI research paths.
- Removed Radar and Vision cheat buffs from the AI.
- Added Naval Neural Net.
- Updated the Neural Net data based on several hundred new simulation sets.
- AI will wait until it has a mass convertor before going nuts with Pgens.
- Land, Balanced, and Rush AIs will put a higher priority on getting an Air factory if they can't reach an enemy by land.
- AI ACUs will no longer build Naval factories. This will be handled by Engineers.
- The AI will once again use the Illuminate Space Temple.
- Adjusted AI platoons to prevent the AI from stalling when hitting unit cap.
- AI can now use Naval units to guard its base.
- Guard base platoons will now guard a wider range.
- AI will build more engineers per expansion base.
- AI will only build up to 10 research facilities.
- AI will take mass fabricators into account when looking at income/spending ratio.
- AI will build Gantries in expansion bases more.
- Improved AI Nuke/Anti-Nuke behavior.
- AI platoons will no longer Jump Jet or Teleport unless at least 75% of the platoon can make the move.
- Platoons that the AI wants to run away will now clear previous commands.
- AI Neural Nets will now check to see if an enemy unit's shield is active when performing threat evaluation.
- AI units will no longer run to deactivated bases.
- AI will now use carriers appropriately again.
- Added a new function to the Platoon class to get a platoons shortest attack range.
- Micro distance is now based on the Platoon's shortest attack range.
- AI will now do a quick pathable check when looking for places to build.
- Engineers will no longer look for things to reclaim or units to repair while attached to another unit.

Known Issues:
- Replays from previous versions will not function with this version.
- Skirmish Save games from previous versions will not function with this version.
- Campaign Save games from previous versions will not function with this version. Campaign progress (unlocks) will still be preserved, however.