Almost every single beat of this game is done better by the first title.
The visuals of the first game are a bit jarring at first, but you can generally sight read everything in a room pretty easily by the last few stages of the Locksmith campaign. In Monaco 2, it was very easy for me to not notice coins on the ground and have to backtrack to grab them. The camera angle lets you see things from afar, but then it's easy to not notice smaller things in a room. Or go top down, where then things can notice you from beyond the reaches of the camera.
Level design is a suggestion because of them deciding to focus on procedural generation and then deciding on a personal favorite seed to use as the "official" version. So there's plenty of dead end rooms, and some rooms that are downright hellish (final room of Prison). There is a very notable difficulty spike at the Prison and then the difficulty goes down from there. To the point that several earlier levels are harder than the later ones to me. Tying into this, items rely on ammo instead of gaining a charge for every 10 coins you grab. The items recharge on a cooldown afterwards, and you have to pick them up again. Thanks to this procedural generation, some levels have incredibly long dry spells of no items with plenty of obstacles in your way. Or you'll come to find that the generation intends for you to use the EMP gun to be able to unlock a safe without being gunned down and have to run back to the nearest one, however far away it is. Also, every level has only 4 characters to pick from, you likely aren't going to get to use the character you really enjoy and if you're playing multiplayer, I'd be willing to bet somebody is left with a character they dislike every time.
There's three returning enemies from the first game, the melee guard, pistol guard, and shotgun guard. These are all fine, the shotgun guards are tankier and require 6 shots from a pistol to kill compared to the 2 for all smaller guards, which basically means you're using the crossbow or shotgun only. There are sniper enemies that function incredibly strangely. They will alert almost immediately once you're in view, and line up a long wind up shot that does a lot of damage. If you break line of sight, they'll drop aggro and have to restart their shot. I genuinely thought they were bugged at my first encounter. They work for their purposes though. There's big shield enemies that you can't hurt at all from the front, and deal increased damage with their melee. The shield enemies also have one incredibly frustrating quirk, if they hit you, they interrupt whatever you're interacting with. They are the only enemy that forcibly breaks your interaction bar. My most frustrating deaths have been being .1 second away of getting into a hiding spot or vent and having it cancelled. That being said, the worst part gameplay wise isn't any single enemy but rather...
The turrets. When the blurb for the game is "skedaddle when things inevitably go awry" these things spit in the face of it. Turrets will melt a full HP bar plus body armour in seconds; once an alarm goes off with a turret in the room EVERYONE inside starts to get shredded to pieces by the turret. So in multiplayer an alerted room becomes a giant roadblock that you can't enter without being wiped out. In the first game, they went off once when you set off the alarm and did damage to only the person setting off the alarm, but the usual threat was the incoming guards and locked doors. Repeated alarm triggers would make it shoot again. In multiplayer especially this means that somebody triggering the alarm doesn't ruin the entire process.
Each character has a unique ability; trinkets that give benefits in exchange for losing max HP. Some passives are NOT worth the insane drop in HP, to the extent that some leave you with 3 HP for effects not that strong. Others have very strong effects and only take away 1 or 2 HP. Some of these trinkets also feel almost mandatory to make characters abilities feel good to use. The trinkets themselves I think are interesting and just need tweaking.
The story and writing is just bad. Monaco 1 was not a masterpiece, but the narrative of an inspector interrogating the thieves to figure out the truth is engaging enough, and I think the Pickpocket is very interesting for a character. Having this finish with the twist of there never being 8 separate thieves in Pickpocket's story, and Fin ending with the twist of Cleaner being the assistant to the inspector to erase their identities makes them feel complete. Not perfect, but I enjoyed the writing overall.
In Monaco 2, you're a lower tier crew of thieves that got caught on recording stealing King Dreg's violin. He demands you test his security and fatten his pockets from siphoning company funds to his personal account. Then he has you steal the hard drive containing the theft. After stealing the only evidence of your crimes, Gibson is unfortunately caught in one of the worst cutscenes in a game I have ever seen. Break him out of prison, grab his devices from solitary, and discover he has a plan to hack into Cyclope security and erase all evidence of their crimes. Using Jobbie, a robot that Gibson made The crew gather the parts he needs, break into the data center, erase all of their crimes and become ghosts in the system. The next mission after, the original crew wants out. With zero evidence Dreg can hold against them, zero blackmail to use... Dreg says they need to do one final job for him, and despite the insistence to not work any further, upon hearing Dreg wants to become the CEO of Cylcope, they immediately give in and start helping.
So the crew makes him the CEO, and he gives one last job to do. Deliver a present to his rival's yacht. Turns out it's a bomb, and for some reason the crew decided to just... sit in the rival's office with the present rather than just leaving it and escaping? Dreg and his group move to kill off the original crew after they survive the bomb. Una betrays Dreg, Pockets betrays the old crew. Gibson makes a desperation play and insists that he can take over ALL the security in Monaco thanks to Dreg being the CEO now. The crew successfully steals into the database... and Jobbie becomes a free thinking agent that allies with the original group (and Una) getting Dreg's crew (and Pockets) arrested. Then it ends with the crew wondering what to do next.
The character writing for dialogue purposes is juvenile at best. Motivations are absurd, and Dreg's crew are oddly aggressive when the original group never even fights back really. Looping back to the fact there's always four characters, the final level of the game is one final stealing spree with Dreg, Cicero, and Pockets stealing as much as they can. Since everyone else is opposing them, they randomly write in that Una decided to help them steal stuff as one last favor to Dreg. Una does not get arrested, she's a part of the main crew now. But she did steal stuff with the others.
The worldbuilding is a bit strange too. They made every single guard in the game a robot this time around. The first game never really suggested sci-fi was an aspect? The closest was gun turrets that shot at where an alert was triggered in the first. But now one of the playable characters is a sentient robot, one has a drone that can open up safes and grab weapons... and nothing else in the world feels particularly sci-fi. It's a weird aspect to include, especially since you can still murder the HUMAN civilians without issue. So... why are the police robots? Why are the ROBOTS able to be knocked out via tranquilizer guns and Cicero's syringe?
Overall: Almost every part of the game is done better in the first game to me. You can get far better and challenging experiences from custom levels made by the community in the first game without relying on procedurally generated levels. If you want a game that uses procedural generation well, go look at rogue-likes.