A decent game worth the price of 500 Wii Points.
Defend Your Castle has many new elements to the gameplay. Besides motion controls, there are now upgrades. For every foe killed, you will gain points. After each day (level), you will be able to use them for upgrades such as more health and the Pit of Conversion. With the pit, you will be able to use enemies as your own. With them you can use them for a Mage tower which attacks enemies with magic or the Archery tower which attacks with arrows. You will need these upgrades because as you go on, more vast numbers and types of enemies will appear.
As a single-player game, Defend Your Castle wears thin quickly. It is best played cooperatively with one or more friends, and up to four people can play simultaneously. The challenge of the early levels is to be the highest scorer and thus gain control of castle upgrades, whereas the challenge of the later levels is pure survival. As your individual efforts congeal into a unified struggle, the frantic fun will yield vociferous strategizing and smiles all around. However, if you play for even a moderate amount of time, the shouts will fade to whimpers and the smiles will turn to winces of repetitive stress fatigue.
The graphics look like them have been made by a 5 year old. Not in a bad way because it has a certain charm to the look. The sound effects get repetitive soon and aren't very good.
This is a very simple game. There isn't very much. The game small but the price for it is great. If you only play it a few times a month it will be worth it. It will be enjoyed to it's full extent though in Co-op Mode.