If you can get into it, ICO is definitely a game that will stick with you for a long time to come.
For visuals of this vintage from a game released in 2001 they really standup and don't seem all that old. The art direction is absolutely fantastic and that definitely helps the game's look stand up to the test of time. I especially love the unique look of the shadow creatures and how they animate. Speaking of animation, everything animates so well from how Ico traverses the environment to how Ico and Yorda interact with each other, it's all done so great.
The audio experience in ICO is largely made up of the ambiance of the environment around you. Water flows from waterfalls, wind swirls in courtyards and the rest of it is made up of the sound effects of Ico and Yorda making their way around trying to find a way to escape the castle. The only music in the game is during the demonstration, at save points, and during the ending/end credits and it's all great.
The gameplay mostly consists of figuring out how to get Ico and Yorda through many different environment traversal puzzles. None of the puzzles are all that difficult, but some will make you think a little more than others. I never felt frustrated with any of them even if a few were slightly annoying, but even those didn't hinder my enjoyment. The other part of the gameplay is when you have to fight off shadow creatures that are trying to abduct Yorda. The combat is for this is very simple with use of only a single button and it works even though it's not the focus and it helps add tension when you are trying to protect Yorda from them.
This was my first time playing ICO nearly ten years after it was originally released and unlike a lot of other games that age poorly after that many years ICO stands tall as a game that has withstood the test of time with grace and style and is a game that is way more than the sum of it's parts. If you can get into it, ICO is definitely a game that will stick with you for a long time to come.