I was both surprised and impressed with the remake of Defender. Some of the missions are a real pain, but for the most part everything's well done in the game. Graphics, sound effects, music (including the option of using your own custom soundtrack from your Xbox hard drive), control, level design, all good.
It could've been longer, some of the ships could've been more useful, yes. But there just aren't many arcade-style space shooters out like this, and I found a lot of Midway's efforts to be quite impressive. It's good for an afternoon of flying around and blowing the crap out of things.