ICO is an action adventure game that was developed by Sony / Team ICO for the Playstation 2. ICO was originally planned for the PlayStation 1, but after two years of development, the team ran into limitations on the PSX hardware and faced a critical choice: either terminate the project altogether or to restart it on the PS2.
An interim design of the game shows Ico and Yorda facing horned warriors similar to those that take Ico to the castle. The game originally focused on Ico’s attempt to return Yorda to her room in the castle after she was kidnapped by these warriors. Ueda believed this version had too much detail for the graphics engine they had developed on the PSX, and replaced the warriors with the shadow creatures. [Info from Wikipedia]
From early beta screens and videos, we can notice that Yorda had a different design and there were some huge shadows enemies, removed from the final version. If you can notice more differences in the screens and concept arts below, please let us know!
Video from the PSX Version: