I'm hoping someone can help me identify an old computer game I played in school.

It was a PC booter game on a 5inch floppy disc. I don't know the type of computer, just that they were giant, grey beasts with very limited color display.

The game was a text based adventure, in the style of Zork, but illustrated. The screen showed the room you were in, but all actions were taken by typing commands. There was no animation, just a static display of the room. You were exploring a large house, that I think was probably a castle. I remember that one of the rooms was a very sickening green, but very few other details.

I never finished the game, so I don't know how it ends. I think the point was probably to escape, but I can't be sure. The game and computers were old when I was playing, about '96ish, so I have no idea when it was made.