Which shows team Ico is a little odd on their concern for graphics... so a remaster would need to be made by another studio =p
On the gameplay side, many people think it is a little bad so a work on it could help a lot.
The game have a very slow pace due to it.
The slow pace is intentional, but having a walk mode in between crawl and sprint recklessly, as well as eliminating the frame rate drops, will help a lot with the gameplay. They have the momentum right, but not the speed. It was mostly the frame pacing that messed up my control of boy. In stable areas I had no problem running around the obstacles and doing things fast.
Plus I would love to see this game in HDR!