- Estimated achievement difficulty: 7/10
- Offline: 47 
- Online: 0
- Approximate amount of time to 1000: 20+ hours
- Minimum number of playthroughs needed: 1
- Number of missable achievements: 2 ["Leave No Man Behind" and "Party Pooper"]
- Does difficulty affect achievements?: Yes
- Unobtainable/glitched achievements: None!
I have given this game a 7/10 for difficulty based off of the fact that so many people have had trouble maxing it out. It seems that the combat challenges are very difficult for some people and have caused the death of several innocent controllers.
Batman: Arkham Asylum is an over the shoulder action game that is sure to please anyone who plays it. The achievements for difficulty are stackable which means that you only need to do one play through. The game’s achievements can be split into four basic categories, story related, challenge related and combo/combat achievements and miscellaneous. Out of those achievements, the challenge achievements seem to give people the most fits. The game has only two missable achievements, "Leave No Man Behind" and "Party Pooper". Out of those two, "Party Pooper" should be the one you’re most concerned with as it is only available at the end of the game right before the final boss fight. If you fail to do it, you’ll be forced to play through the entire game again. "Leave No Man Behind" on the other hand happens very early in the story, so missing it isn’t that big of a deal.
Step 1: Preparation
Before we begin, you need to pull up a collectibles guide to follow as you progress through the story. Although none of the collectibles are missable, it’s best to collect as many as you can in each area since they give you experience for more upgrades. I personally used swaggers’ guide for collectibles and found it very useful. You can find his maps and videos HERE. As you’ll see when you look at his guide, you cannot collect every collectible in an area the first time you visit. This is because some collectibles require you to have certain Batman gadgets that aren’t rewarded until later in the story. Although the game is fairly straightforward, you may also want to follow a walkthrough in case you get lost. I found this walkthrough to be very useful with it's easy to follow guidance and pretty pictures.
Also, before we begin, it’s important to mention how the health and experience system work. Batman’s health goes down when he is hit by an enemy or other harmful medium (obviously). What makes this game different is that in order to restore his health you need to gain experience. This is done in three ways, killing enemies, completing objectives and collecting Riddler clues/trophies/chronicles/etc. With that in mind, it’s important to realize that although you may be hurt after a big fight, finding a few collectibles will usually put you back at full health.
Experience is important because it allows you to purchase upgrades for Batman. A lot of people struggle on what to upgrade first and what’s important and what’s not. Below is my personal take on upgrading.
NOTE #1: I always had one upgrade remaining at all times to go along with my armor upgrade strategy below or to knock out certain achievements.
NOTE #2: Upgrades don’t save unless you get to another checkpoint. This is useful because you can purchase worthless upgrades early, get the achievement for them and then reload your checkpoint to spend the upgrade on something more useful.
·Combo Upgrades – Perhaps the most important upgrades you have available. Upgrading these early will make large fights much easier.
·Inverted Takedown – I personally did not use this at all in story. I wouldn’t get this until you start the Predator challenges.
·Armor Upgrades – Save these! Too often people upgrade their armor too soon. I suggest not using these until you’re in a big fight. Reason being that once chosen, they fully restore your health. This can give you a much needed second wind in the middle of a fight.
·Batarang Upgrades – Of all the batarang upgrades, the only one I used during the story was the multi-batarang. It’s great for taking out big groups as well as the Mutated Titan Plants’ projectiles. The remote control and sonic batarangs weren’t needed until I started the predator challenges.
·Explosive Gel Upgrades – Save these for much later too. I didn’t need them at all during the story.
·Cryptographic Sequencer Upgrades – I suggest getting the range upgrade early as it is needed to get several Riddler clues. The upgrade that makes it easier to crack the code is your choice. If you’re having difficulty, you may want it as the Joker rigged boxes will kill you if you take too long to crack them.
Step 2: Play Through on Hard Difficulty
With the preparation out of the way, begin a new game on the hard difficulty setting. As we go through this step, I’m going to point out locations to get many of the game’s miscellaneous achievements as well as the missable achievements. The only thing you need to do in between these locations (other than progress the story) is to follow the guide linked above and collect as many Riddler clues as possible.
TIP #1: Press to enter detective mode each time you enter a new area. This will give you immediate feedback as to how many enemies there are as well as where they are.
TIP #2: I made a thread about the incredible usefulness of your explosive gel. You may want to read about it before beginning. The thread can be found HERE.
After the opening sequence of the game, you’ll begin in the Intensive Treatment building. Very early on in the building, you’ll come upon a room filled with gas. Once you enter this room, you’ll need to pull up the two guards and one henchman that are about to fall. This will net you the missable "Leave No Man Behind" achievement. A little bit farther into the building, you’ll enter the Intensive treatment lobby and your first predator sequence. Predator sequences are characterized by gargoyles you can grapple to and several armed guards. What you want to do here is purchase the inverted takedown upgrade and go for the "Rope-A-Dope-A-Dope" achievement. The guard in front of you after you exit the vent is in great position for this achievement. After the "Rope-A-Dope-A-Dope" unlocks, reload your checkpoint so you can spend the upgrade on something more useful.
Your next opportunity to get miscellaneous achievements comes once you exit Intensive Treatment and go outside to get the Born Free achievement. After this, purchase the remote control batarang upgrade and go for the Catch! achievement. Again, reload the checkpoint after getting this since the remote control batarang isn’t a necessary upgrade this early. Next, as you start collecting Riddler clues in Arkham East, you will have to climb to the top of Arkham Mansion. This is a perfect time to grab the "Night Glider" achievement.
Your next opportunity to grab some miscellaneous achievements comes immediately after entering the mansion for the first time and getting the "Breaking and Entering" achievement. Upon entering the main hall of the mansion, you’ll notice 10 henchmen on the floor below you rummaging through books. From the vent you’re standing on, glide down to the open area in front of the statue and allow them to attack you. This is a great spot to nab the "Freeflow Combo 40" achievement since this is a very open area with many unarmed enemies. The next area to pay attention to is the secret lab in the Botanical Gardens. Upon entering the lab, you’ll face two Titan henchmen. This is a great opportunity to grab the "Mano-A-Mano" achievement. Simply let the Titans run into each other and attack when you can. Be sure not to use any gadgets on them!
Our next location is after you leave Croc’s lair and have deactivated the three water pumps on your way out of the caves, before you leave you’ll be faced with a Titan henchman accompanied by a myriad of henchmen. This presents you with the perfect opportunity to go for the "Freakshow Rodeo" achievement. Plus, smacking the henchmen around with the Titan henchmen will really help clear out the room.
My next suggestion is optional, although I highly recommend it. After you defeat Poison Ivy in the Botanical Gardens, you’ll see fireworks outside the Visitor’s Center in Arkham West inviting you to the final battle. This is a great time to finish collecting all of the Riddler clues and snag the "Crack The E Nigma" and "World’s Greatest Detective" achievements because you have all of the required gadgets and there are no more enemies left. It is possible to collect everything after the final boss fight but I figure why not go into it fully upgraded?
NOTE: If you approach the Joker face outside the visitor’s center, one of the four henchmen there will start to talk to you. Don’t worry, this won’t mess anything up.
Now that you’ve gotten all of the collectibles out of the way and are fully upgraded, head to the visitor’s center in Arkham West. Outside you’ll see 4 unarmed henchmen. This is a perfect time to go for the "Freeflow Perfection" achievement because this is an extremely open area with not too many unarmed henchmen. After you’ve taken care of the four henchmen outside, head into the door where you’ll find around 20 henchmen applauding your arrival. WARNING! MISSABLE ACHIEVEMENT AHEAD! This is the location where you get then Party Pooper achievement. To get it, you must beat up all the henchmen in this room. The method I used involved explosive gel. Simply lay three evenly spaced explosive gels on the floor and detonate them at the same time. Then, while everyone’s down, use + to start thinning out the ranks. From there, it’s all on you to take care of the rest.
With the missable "Party Pooper" achievement out of the way, the only thing left to do is finish the game. Upon completing the game, you should receive the "Big Bang", "Bigger Bang" and "Biggest Bang" achievements for completing the game on hard.
Step 3: Predator Challenges
If you followed my advice above, the only achievements you should have left are the ones related to challenges and "Perfect Knight". We’re going to do the Predator challenges first since I think they’re easier than the combat ones. To earn all the medals in each predator challenge, you must complete three objectives per challenge. To find out specifics on what these objectives are, press while in the challenge. The only big difference between the extreme challenges and the regular ones is that the gargoyles are rigged to explode which actually isn’t a big deal once you figure out how to stay hidden.
Before we start going for the medals, though, I suggest you go for the "Invisible Predator" achievement. There’s no specific map to suggest for this one, but I wouldn’t suggest an extreme one. With that out of the way, it’s time to get all 24 predator medals. To complete all eight of these challenges, I used the videos located in the achievement guide as well as the tips mentioned in this thread. With those two resources I finished off the predator challenges with relative ease.
Step 4: Combat Challenges
This is the step that has caused more fits and more problems for players than any other. To earn medals in these challenges, you need to obtain a certain number of points. As an added challenge, the Shock and Awe challenge maps have an imposed time limit per round that if you don’t knock out all henchmen before time expires, the challenge ends. Prior to going for the medals, though, I would suggest loading up the Intensive Treatment challenge and trying to get the "Flawless Freeflow Fighter" achievement. After you get that achievement, you may also earn three medals in the Intensive Treatment challenge because of the Perfect Knight bonus you earn at the end.
It’s now time to get three medals in all the combat challenges. It’s really not hard once you practice a little. Below are a few tips you can use in addition to the ones in the achievement guide:
-This is not a button masher. Carefully plan out your next move. Button mashing will only ensure that your combo gets stopped frequently.
-Relax. These aren’t super easy to do. Getting frustrated and angry will only hinder your attempts at three medals.
-Above all, keep your combo going. Although variation is important, getting high combos is the best thing you can do to ensure you get lots of points.
-Variation is important. If you can pull off a freeflow perfection, you will get an additional 5000 points at the end of the round. However, don’t sacrifice your combo with a risky move just to get more variation.
-The first round is crucial. Getting a high point total in the first round will set the tone for the entire challenge as well as give you a little leeway in the later rounds in case you mess up.
-Use the evade move liberally. You can evade after each successful attack. This can give you a couple precious seconds to plan your next move. Just be sure not to evade twice in a row or it will kill your combo.
-If everyone is down on the ground, use the + takedown. This will not only increase your variation bonus, but also give others time to stand back so you can continue the combo.
-Watch the sides. Be sure to watch the sides of the map as you’re moving around. Odds are if an enemy is standing there, he’s either trying to get a rifle out or pull out a cinder block to throw at you.
-Know your enemy. Shock stick and knife henchman cannot be attacked directly, if you do, your combo stops. To hit them, you must either jump over them for shock stick henchmen or stun them with your cape for knife henchmen.
-Use the slow mo to your advantage. While in a slow mo takedown, you should survey the scene to figure out your next move. The slow mo scenes also give you brief invincibility.
That’s it! If you completed everything above you should be 100% complete with the game and have received the "Perfect Knight" achievement. If you’re missing something, refer to the appropriate step. Last, I’d like to thank swaggers for his wonderful work on the collectible guide, it was very useful.