Certainly. I’ll actually wrap it into a small sample project, so that you can compile it as-is and see how it works.
[spoiler][code]
Alpha, Beta, Gamma, Delta, Epsilon, Zeta, Eta, Theta, and Omega are rooms.
Alpha is north of Beta. Gamma is west of Beta and southwest of Alpha. Delta is below Gamma. Epsilon is south of Beta. Zeta is southeast of Epsilon. Eta is below Zeta. Theta is southeast of Delta and northwest of Eta.
The airlock is a locked door. “The airlock is [if the airlock is open]open[else]closed[end if] to the [if the location is Alpha]north[else]south[end if].” It is north of Alpha and south of Omega. There is a passcard in Eta. The passcard unlocks the airlock.
Every turn when the player is in Omega:
if the airlock is closed and the airlock is locked and the alien is not in Omega:
end the story finally saying “You have escaped”.
The alien is a person in Zeta. “The alien has arrived, and looks angry!”
The alien can be currently feeding. The alien is not currently feeding.
The player carries a blob of alien meat. The description of the meat is “Green and squishy. You have no idea what it is, but you’ve been told that aliens like to eat it.”
The blob of meat has a number called the feeding duration. The feeding duration of the meat is 5.
Every turn when the alien can touch the meat and the meat is not carried:
now the alien is currently feeding;
decrement the feeding duration of the meat;
if the player can see the alien:
say “The alien is contentedly eating the meat.”;
if the feeding duration of the meat is zero:
remove the meat from play;
now the alien is not currently feeding;
if the player can see the alien:
say “The alien finishes the meat and turns toward you again.”
Definition: a direction (called the way) is alien-usable:
let the place be the room-or-door way from the location of the alien;
if the place is nothing, no;
if the place is a door and the place is locked, no;
yes.
Every turn when the alien is not currently feeding:
let N be the number of moves from the location of the alien to the location, using doors;
let the way be a direction;
if N is less than 5:
say “You sense that the alien is [if N is 1]in the next room[else if N is 2]very close now[else if N is 3]close[else if N is 4]somewhere nearby[else]in the vicinity[end if].”;
let the way be the best route from the location of the alien to the location, using doors;
else:
let the way be a random alien-usable direction;
if the way is a direction:
if a random chance of 3 in 4 succeeds:
try the alien going way.
Every turn when the alien is in the location and the alien is not currently feeding:
say “The alien has found you!”;
end the story saying “You die a horrible death”.
[/code][/spoiler]