I'm on the fourth world now and yea....it IS getting real monotonous now. I guess it can't be helped. Fight some ogres, walk a few feet, fight some more, repeat. It gets boring after awhile.
Luckily, the bosses are worth the wait. They tend to take up both screens!! In fact, when they appear, Thor actually gets even smaller than he already is. It's almost overkill.
I heard HD versions were the worst. It goes DS>Wii>360/PS3.