This is grind heavy MMO that relies almost entirely around gear progression that allows players to eventually solo bosses. This game "doesn't get good" until post level 200 which can take anywhere from 15 - 30 hours for a fresh account to achieve but if you enjoy the music, art style, and using cool looking skills to kill as many mobs per minute as possible the grind to 200 shouldn't be too bad. Just expect things to slow down around level 160, this is normal and most people find it to be a slog.

Whether or not you personally enjoy this game is going to be largely subjective and depend on what kind of things you like doing in games. As stated above the onboarding section of this game is largely going to be you sitting in different maps spamming flashy skills and watching your EXP bar fill up. There are a ton of quests littered around every town and map but largely (even after a somewhat recent update increasing their EXP rewards) quests are much less effective and slower method of leveling your character compared to grinding mobs. Aside from the lack of optimization a lot of the quests (while funny at times) are pretty dull and don't hold any impact or relevance until post level 200. The one exception to both the lack of EXP and the lack of engaging content is the games numerous "Theme Dungeons" which are essentially small areas that have a contained storyline that is completed through a series of quests. Not only do these quests give you massive amounts of EXP and are typically the most effective way to level your characters (at least before you start power leveling, more on that later) but the story is usually very well written and fun to experience for the first time. Once you hit level 200 the grind continues but it becomes somewhat optional. You unlock daily quests at 200 that give lots of EXP and free stats in the form of upgradeable equipment. The overall story gets a lot more interesting post 200 so if you're looking for an MMO that has a good story just know that you'll have to get through the first 200 levels first.

For me the big draw for most MMO's is the main progression system, in Maplestory that system quickly turns from leveling up to gear once you hit level 160. One of the best parts of Maplestory in my opinion is the boss fights and gear progression is integrally tied to fighting bosses as you progress. Most people who play Maplestory make their goal to eventually be able to solo the end game bosses which requires a mixture of both good gear and good understanding and execution of complex and intense boss mechanics. If this sounds like something you would enjoy I would encourage you to try the game out and if you find yourself not enjoying it in the early game try and push yourself to get to level 120 and start doing some bosses.

So a lot of this review has been positives, so let me get into the negatives now. I'll do my best to explain these the best I can and please take in mind that I chose to put over 3000 hours into this game despite these issues.

The Cash Shop
Being a free to play MMO Maplestory has a in game shop that allows players to use real currency to buy a variety of things. If you are playing in a reboot server the only items you can buy are cosmetics and pets. Cosmetics only change your in game appearance but pets are basically essential if you want to play the game. Pets will follow your character around and automatically pick up any loot that monsters drop for you. This is important because the alternative is either mashing your pick up item key for every item that's dropped or standing still for a few seconds and holding the pick up key to loot. This will SEVERLY slow down your ability to grind and kill mobs and henceforth will greatly extend the time it takes to level. You do start with a pet that lasts 10 or so hours play time when you start a new character on reboot but its unlikely that you'll be able to get to the point where you can get free pets in that amount of time. This essentially makes it necessary to purchase a pet from the cash shop for around $10. This pet will last for 90 days but can be revived for free using rewards points which can be earned every day and this will last you until you can start getting a unlimited supply of free pets from a certain boss. Now if you aren't in a reboot server things get a whole lot messier... The main method to power your gear up is by buying an item from the cash shop and using on your equipment for a chance at better stats. This means you either have to make enough in game currency to trade for pre-upgraded equipment, shell out what is typically hundreds of real dollars to upgrade your own equipment, or find a reliable way to make large amounts of in game currency so that you can trade it for NX cash which can be used the in the cash shop.
TLDR: Play on reboot.

Glitches, Crashes, and Lag (Or just Nexon in general)
Nexon America has a terrible reputation for not understanding how to run their game and the servers often crash entirely or lag horrifically whenever a new major event or content patch is performed. Also because 90% of the patches and updates come from Nexon Korea they are usually riddled with bugs, issues, or incorrect translations shortly after release. The game itself also has a somewhat shotty anti cheat and many players are incorrectly banned for either "cheating / abusing glitches" or "harassment" without warning. Some players who attempt to contact a Nexon GM to have their account unbanned are either completely shrugged off and ignored or there are even some horror stories of players having their temp ban turned into a permanent ban due to running into a bad GM.
TLDR: Nexon America kind of sucks

Burn Out
A lot of the big seasonal events that Nexon releases require you to play the game everyday usually for a minimum of an hour (sometimes/most times more) in order to get the best rewards. These rewards are usually things that speed up progression immensely and are very highly sought after. There are even some best in slot pieces of equipment that are event exclusive that only show up one a year / once ever. This in my experience has lead to a feeling of needing to play every single day and has led to extreme burnout which has made me quit multiple times.
TLDR: Events can feel like they are forcing you to log in and play every day for extended periods of time

Overall I love this game (I mean come on... 3000+ hours) but I've had to leave it for good as I don't have the kind of time to dedicate to it anymore.