A great game with well implemented RPG elements.
There are a lot of characters, each with their own unique abilities and play style. After each battle, you get experience and IP. IP can be used to buy characters and glyphs for your characters. as you level up, you unlock more slots for glyphs which provide minor, but useful effects such as a higher critical hit chance, dodge rate, maximum health etc. veteran players aren't extremely over powered though, which is great. Also there's a World of Warcraft-esque talent tree.
One problem is that since a lot of the players are very experienced, they don't take too well to people that aren't very experienced.