It's been over a year (!) since Magicka came out. There are STILL major bugs.
Multiplayer - frequent lost connections, crashes and desync issues with shields and spells. No dedicated server options.
Havindr is zoomed too far in, so you get killed by a rock from the other side of the screen while you can't see the other player. There is also the fact that you fall through the map if you get catapulted. Another issue that has been brought up before is the one of the ready button. How hard would that be to change, and why, why, why do I have to wait for someone to push ready before I can take the game back to the lobby? It doesn't make sense and still hasn't been addressed.
Single player - challenge maps where scripted events fail. In Marshlands, several waves don't trigger, forcing you to run around the edges of the maps and fire projectiles off screen to kill the enemies. In Cavern, enemies can fall over the side and land on a ledge. The only way to kill them is to fall off the edge, use an AOE spell, hope you kill the creature, and teleport back onto the ground before you die. Ridiculous.
The point is, I paid for a product...that is STILL faulty. After a year and 1.3 million + copies sold, this game has made enough money now that, if you can't fix it yourself, you can hire someone to fix it for you. Do right for your customers or you'll lose them. I already stopped recommending this game because of all the bugs and problems associated with it.