Imagine if old GTA games, Chip's Challenge, and Ocean's 11 all stumbled into a blender owned by a Lego man.
Boy what a mess that would be. Thankfully, Monaco is 'not' a mess, but rather, a stealth heist game in which you and up to three other thieves band together to plunder the money of a variety of facilities in and around Monte Carlo, everything ranging from Casinos to Hospitals to High Security Prisons, being represented.
The game's two virtues are its deceptive level of gameplay depth, and its humorous design aesthetic. It's the personality hidden behind the neon pixels that at first attracts one to this game--the perplexingly simple yet expressive character designs go along with the frantic piano ragtime and silly french NPC voices, to be extremely memorable. You'll laugh as your little colorful lego thief pees in a toilet, wiggles their hands to hack a PC hollywood style, or hugs a wall and takes deep, ragged breaths after being shot--to the accompaniment of bloodied footprints left in their step. And as your little Mr. Pink dies from that one guard who peaks just inside your hiding place to bop you with a wrench, they explode into a neon pink colored skeleton, and the music thuds to an abrupt halt--only for the music to pick up again where it left off, once your fellow criminals put your guts back in (to the sound of hilarious squishing noises).
As for the gameplay, it's definitely the part that keeps you playing Monaco, long after you're familiar with its pretty pixel face. On the one hand, you can be a sneaky, super subtle player who never gets caught, never trips a trap, never fires a shot. It can at first be a difficult process to do so, as you're forced to learn by trial and error (due to the game's sparse tutorial elements) how to remain undetected.
On the flip side, however, Monaco, unlike some of its compatriots in the sneak-em-up genre, never trips over the hurdle of forced stealth. You can shoot people down in a bloody Scarface-esque machinegun massacre, lure guards and civilians into side areas off patrol and give them a wrench over the head, 40's femme fatale style, or be a clever ♥♥♥♥♥♥♥, cut the circuit breaker in a particularly well-guarded facility, and just 'camp' the power room subduing guards who come with chloroform, while your (debatably) coordinated teammates do the legwork.
In fact, if you're in a hurry, it can sometimes be better just to run aggressively past NPCs, dodging from cover to cover to avoid security agent machinegun fire, or to climb in a vent duct to escape angry attack dogs who are onto your scent, rather than trying to outstealth them. And as a result of this flexibility, at first, it seems like Monaco will be trivially easy to play and win.
But Monaco is a stern teacher, and it knows how to steadily ramp up the difficulty to keep you challenged through around thirty-some different, replayable missions. As you go, new classes and items are introduced to the formula, along with new map features like security-trigger handscans, computer viruses, alarm-triggering ATMs that must be busted open for cash, and more.
The game is incredibly flexible in its approach, and each class is nuanced enough to be distinct from its brethren. (The one class I am not personally fond of is the Pickpocket, which tends to encourage reckless, self-serving tactics over cooperation, at lower levels of play experience.) However, the classes are not so distinct that they cannot all perform basic functions like opening a safe, or hacking a PC--it's just that some classes do these things more efficiently than others. So there will rarely be a point where you play a mission 'exactly' the same as the last time you played it, as you tackle obstacles in a level best suited to whatever class you are playing at the time.
Lastly, there 'is' a story to the game, consisting mostly of text dialogue, but which is filled with humor and an actually relatively intriguing plot, fleshing out the personalities and origins of the thieves you play as. The thieves themselves have some pretty charming tics--the Hacker is constantly making references to PC error codes and computer shorthand terminology, the Gentleman is your 'World's Most Interesting Man', complete with his own little intrigue and espionage plot, the Cleaner is a stoic psychopath who rarely speaks beyond deep heavy breaths, and the Mole has a terse Serbian accent and a Freedom Spoon which he employs with a mixture of bravado and thuggish loyalty.
The game does suffer from a poor matchmaking system, which is a bit prone to lag and connectivity issues. Also, the menu options are a bit confusing, and there is one bug with using a controller that prevents mouse usage until your machine is restarted--so if you tend to use a controller for some games, like Gauntlet or Dark Souls, but prefer a mouse and keyboard for Monaco, you may run into complications where your mouse doesn't want to work to aim guns til you pull a soft reset on your OS.
All in all, I give Monaco a thumbs up. There are a lot of visual tweaks that could probably make finding your way in the maps a bit easier, the story could use some accompanying visuals (even if just still scenes), and the tutorial aspects of the game are sorely lacking even after a custom tutorial map was added--but the game just has so much complexity and charm, that it's hard not to pick it up from time to time, if you can get past those hiccups long enough to get into the meat of the game.
Grab it if you don't have it, and see if you can't wrangle some friends into the heist with you on headsets. At worst, it'll make for an amusing weekend of cartoon criminal hijinx.