After not playing for sometime i tried to play this game again but unable to reinstall back this game? it said content file lock?

I was browsing steam and I noticed that two of the characters are indentical to Kayah and Helen from Celestial Hearts, in both their portraits and sprites. Why is this? Celestial Hearts was released two months before this game.

I liked the classic look of this game so thought I'd try it out but, have been having problems with the game freezing during combat. - It seems like a graphical issue as i can still hear the menu bleeps when I use the arrow keys but but am stuck with the same picture (usually from the beginning of the battle) - I'm almost certain the second time this happened because 2 enemies ran to my player at the same time, unless this was a coincidence. I'd tried minimising and then maximising to no avail. As there i...