Its a very nice game, but its a "go in room, fight, wash, rinse, repeat" kinda game. You pick your class (archer, mage, blacksmith, warrior, ninja) then pick/make a game room and go in and fight. There are a few different game modes, they have solo deathmatch, team deathmatch, golem (kill the gold golem, then whoever kills that must kill the other teams golem), stage (like quests), and boss war (kill the other teams boss)! It's a veryyyy nice game, but because of the constant repetition it can get boring to many players. However it stays exciting for many people also, cause you are constantly striving to win, and get better, and compare yourself to other players. You do of course get xp and raise levels. You can buy different armor/weps out the shop as you get gold/xp from fighting. A neat feature of this game is you can have "cells" which are creatures that u can summon to help you fight. You also buy these out the shop, and they get xp as you get xp and level up accordingly. Basically, try the game, its very nice!
Now about a private server. I've looked for a private server for this game and have failed miserably. I doubt sum1 here will have the source code, but lets hope sum1 does!