Too boring and repetitive. Click on monster... wait for it to die. Repeat as necessary to complete level.
Click on a monster and your character does the same boring attack over and over and over until the monster is dead. Don't worry, hundreds more of the same monster will appear and you can repeat the click & wait process as many times as you like until the appropriate amount of time and brain matter have been expended to make you want to delete the game and go do something fun and hopefully more challenging and intelligent.
For those that value your braincells and leisure time, don't waste your life energy on this junk. This game is definitely targeting the lowest IQ portion of the gaming market. Better to play a real RPG like the Fallout games, Icewind Dale, Baldur's Gate, or the Temple of Elemental Evil.
If you insist on playing Dungeon Siege, have a box of tissues ready to dry your tears of boredom and keep your dog away so you don't kick him.