The flying desert colossus was also kind of a bitch because I couldn't seem to get Agro (the horse) to meet head-on with its wings so I could climb on. I also had some trouble with the two dog-like ones with the plated armor, because they'll knock you down over and over, and Wander (the boy) takes an eternity to get up after getting knocked down. Most of the others didn't pose much of a problem at all. I'll play on hard mode whenever I come back to SotC.
It's an amazing game, and truly one of a kind. At the moment I don't really have a favorites of all time list (longer than 3 titles, anyway), but this SotC would definitely be a candidate. My only problems are with the camera sometimes being at a bad angle for judging jumps on a moving colossus, and the fact that Agro doesn't always do what you want him to, but I suppose that's just realism. If they ever did a sequel, I'd also expect there to be more than one way to scale and take down the colossi. A little more free-form problem solving and a little less being funneled through a specific sequence of actions would be nice.