Though Rocksteady is staying in and expanding the Arkhamverse with the upcoming Suicide Squad: Kill the Justice League and WB Montréal is going elsewhere in a Batman-less Batman multiverse with Gotham Knights, Bat-fans will always lovingly remember and dive back into the revolutionary Batman: Arkham series. While Christopher Nolan effectively revived the superhero theatrically from 2005-2012, Rocksteady did the equivalent in video games from 2009-2015.

RELATED: 5 Things Batman: Arkham Knight Did Right (& 5 That Were Disappointing)

Batman: Arkham City is generally regarded as the crowning achievement of this illustrious series. It improved upon its predecessor in every possible way and then some. But for all the emphatic --and deserved -- acclaim the game received, nothing is perfect, so here are the seven best things about City and the few that could've used improvement.

10 Best: Meaningful Open World

The open world of Batman: Arkham City

Open worlds are commonplace in video games -- for better and worse -- and Batman: Arkham City took advantage of the hardware capabilities and success Arkham Asylum brought/built a foundation for. Players have seen examples of games released that implemented open worlds that felt like they were created just for the sake of saying they had one, even if the content inside was sporadically-placed at best. Arkham Origins was one of such open-world games criticized for this.

City did well to craft an open-world well beyond what Asylum has in scope. More importantly, the sandbox wasn't barren, with gangs of thugs, Riddler trophies/riddles, side missions along with the main story packing Arkham City with fun, engaging, and satisfying content throughout. Plus, it improved/emphasized gliding heavily, making it a joy to traverse the appropriately dark, gritty super-prison.

9 Needed Improvement: More Batfamily Focus

Tim Drake and Dick Grayson as Robin and Nightwing in Batman: Arkham City

To be fair, Arkham City certainly improved upon this aspect from its predecessor, though it still felt like more could have been done. The biggest addition in this respect was adding Catwoman as not just part of the story, but a playable character, which proved a fun gameplay twist. Though, other key characters were sidelined.

But while Alfred gets more focus (in audio), Oracle takes a back seat and Tim Drake's Robin only makes a brief cameo. Dick Grayson/Nightwing is there, but only as a playable character in the challenge maps. Also, Commissioner Gordon is largely absent, which is disappointing because their friendship/partnership dynamic is a lynchpin in Batman lore.

8 Best: Side Missions

Deadshot, Hush, and Mad Hatter are featured in side missions in Batman: Arkham City

Like with open-world games, side missions are crucial to creating a longer, more enjoyable gameplay experience. Naturally, Arkham City needed to add more of this, especially with using a superhero that has arguably the best rogues gallery in comic books. Asylum's only real side mission was solving Riddler's riddles and collecting his trophies.

RELATED: The 10 Best Villains In The Batman Arkham Series, Ranked

City expanded on that mission greatly but added several other side missions starring more supervillains from Batman's expansive list of supervillains to focus on some other compelling stories. These side missions were well-executed in expanding the number of hours to be put into the game playing exciting content on top of the challenge maps outside of the story mode.

7 Needed Improvement: More Expansive DLC

Robin as the main protagonist in the Harley Quinn's Revenge DLC for Arkham City

While on the topic of the Batfamily, Robin could have used more screen time, even in DLC form. The Harley Quinn's Revenge DLC did add a couple of hours or so of fun story content with Tim Drake/Robin as the main protagonist, but he should have gotten more attention still. If he wasn't set to have a major role in the main story, perhaps making a great, four-hour-long expansion with him could've satisfied more and focusing more on his relationship/dynamic with Bruce Wayne.

Even Nightwing could've used screen time in DLC since he's only a challenge map character. Something that incorporates one or both characters in Arkham City doing specifically-tailored side missions would've also been welcomed.

6 Best: Boss Fights

Batman against Mr. Freeze in a boss fight in Arkham City

With such an exciting cast of supervillains, boss fights deserve to get fun, creative treatments in a Batman game. Arkham City expanded on bosses that felt like a proper evolution of Asylum. The biggest one to come to fans' minds is the famous Mr. Freeze boss fight. Given the tragic villain's enhanced suit and weapons, the fight tasked players to delve into Batman's stealth expertise to earn a victory.

Batman was stripped of vantage points and had to use different stealth-takedown tactics every time, with Freeze adapting after each takedown. This got tougher in New Game Plus. Though the Ra's al Ghul boss fight provided a great, trippy, Scarecrow-esque encounter, and the Solomon Grundy battle was also an effectively entertaining one.

5 Needed Improvement: Required More Setup For Arkham Knight

Batman and the Arkham Knight/Jason Todd in Batman: Arkham Knight

Hindsight aside, but while the story of Arkham City was well written and Arkham Knight proved to be a great game and satisfying finale to the trilogy (in spite of its blemishes), the former could've done more to set up the latter. While also a bit of a knock-on Knight, given Rocksteady were responsible for the whole trilogy, this can be viewed as an area of improvement for bothAmong the biggest narrative complaints of Knight was that the 'twist' reveal of the Arkham Knight's identity was no twist. It was exactly who almost everyone expected it to be: Jason Todd, the second, formerly-deceased Robin.

RELATED: 5 Things Batman: Arkham Origins Did Right (& 5 That Were Disappointing)

City comes to mind because, outside an easter egg, Jason wasn't really brought up. Certainly not meaningfully. Knight's story was thematically good, though it wouldn't have taken the same level of heat if Jason was appropriately alluded to instead of it pretending that his identity is a mystery to the player.

4 Best: Hugo Strange

Hugo Strange as a major antagonist in Batman: Arkham City

A welcome narrative innovation to the Arkham series is including a different, underused, but dangerous supervillain for Batman. This was perhaps the first time that Hugo Strange, deranged psychiatrist, became more appreciated in the mainstream. Given that this is a video game series set within the greater DC multiverse and not a long-running comic series, this overall Batman story is allowed to have a more concise beginning, middle, and end.

Therefore, having a threat in Strange that has manipulated those in power to devise this super-prison in order to feed his sadistic obsession with Batman, and knowing his identity, allows for actual consequences/conclusions to occur and heavier stakes. Plus, Strange presents an exciting, deeply psychological threat to Batman.

3 Best: Ra's al Ghul

Ra's al Ghul as the true mastermind supervillain in Batman: Arkham City

He's already been introduced into the mainstream properly thanks Batman Begins, but seeing Ra's al Ghul prominently in the Arkham series was fantastic. Having Ra's revealed to the true mastermind behind Arkham City was well-written and earned. It didn't undermine the significance of Hugo Strange's threat to Batman and the rest of Gotham City, but conveyed the arrogance and hubris the former possessed in a thematically-appropriate manner.

Ra's himself has proven in every medium he appears in that he is among Batman's most formidable foes. He's one of the few that challenge him mentally and physically, as well as respecting him.

2 Best: Combat Innovations

Free-flow and stealth combat were greatly evolved in Arkham City

It can be said for every Arkham game, but it doesn't change that the improvements to combat made in City are one of the best things about it. This goes for combat free-flow combat enhancements and stealth-combat sequences. Particularly with the free-flow, new animations, combos, and gadget-based combos breathed new life into the action in ways that allowed for even more flowing, creative liberty.

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Likewise can be said for stealth sequences, as new takedowns and gadgets granted more freedom in hunting down armed thugs.

1 Best: Killing The Joker

Arkham City made a bold choice in killing off the Joker

As mentioned, since this isn't a comic book series spanning hundreds of issues, more bold narrative choices can be made with more concision. Without a doubt, the biggest choice made was actually killing off the Joker. He's the most famous supervillain in Batman's rogues gallery and is synonymous with him. Yet Arkham City brought a conclusion (of sorts) to his character through death.

It was a dark, shocking ending that accentuated their warped characteristics and toxic, abusive relationship with each other as Batman admits that in spite of the hell Joker puts him/everyone through, he would've saved him. While Joker's gone, something within Batman changed.

NEXT: Batman Arkham: The 10 Best Suits In The Series, Ranked