You should be careful about releasing a game based on a real game by another author. I mean, text adventure or not, if you're using the same name and the same characters/premise and sound clips from the actual game, then you are treading some dangerous water. Nothing will probably happen since you aren't trying to sell the game, I'm just saying be careful about the way you approach promoting it. You should probably ask the developer if you haven't already. Though, like I said you'd probably be in the clear as long as you aren't charging people to play or asking them to "buy" it in any particular way!
Sorry for being a Debbie Downer! Hope the experience has been very fun for you at least!