Maple Story Royals.It is a private server as the original maple story game got trashed by them adding too much stuff. This is the original game where there are 4 classes.
https://mapleroyals.com/?page=index

Also, you don't spend money on this game. They have a place where you vote for this game each day and they give you free NX which is ingame money to buy anything you want. :)
They just finished more coding and upgrades to the game after 6 months. Just reopened today.

When you make your character, make sure if you want to be a mage when you get to lvl 8, that you add SP to int and luck at lvl 1+ . If you want to be a zerker add to strength. Bowman takes a lot of dex. I had to make another character because you cannot reset your AP(ability points at lvl 10. They stay as you made them in the beginning. When you are a high level,you can buy an AP reset book for 10 million coins.
Mage is the only class that you can become a mage at lvl 8. The other classes can be had at lvl 10.
My ingame name is RoxxOnFire. I couldn't use the name I made my 1st character as shown in the screenshots.
The game is Completely FREE.