Realm of the Mad God is a free to play online multiplayer game. It's a mixture of multiplayer roleplaying and the 'twin-stick' shooter like Geometry Wars.
That makes Realm of the Mad God sound strange, and it is. But it's great fun. You begin with a Wizard, and have to enter realms to complete quests, gain XP, level-up and get fame. Teaming up with other players is totallly organic, and fighting in teams actually makes the game a lot easier, which encourages team play.
You level up with your character until it dies. Then you start again with a new one. When you die you earn fame points, which open up new characters to play with, and mean you can start the next game with better odds. The RPG elements center around buying items for your character and earning XP, while the action is like a fast paced shoot 'em up with a fantasy setting!
The retro 8-bit look of Realm of the Mad God is great - it's not only stylish and fun, but practical too. When things get busy, and they will, you can clearly see what's a bullet and what's not. It's a free-to-play game, but the premium parts don't break the game for free players, which is great.
Realm of the Mad God is highly original, and a great mix of game styles that combine to make something highly playable and addictive