ZENO - an Adventure Game for the IBM PC

Freeware by David Mitchell

Here's a screen shot of ZENO:

ZENO is a small game, but it does illustrate some quite elaborate ideas. For example:

it allows quite complex input commands, such as

  "take the small green card and put it in the battered box"

  "turn the knob on" and "turn on the knob"

some verbs, such as PUT, can be used in several ways (PUT something IN or ON something or just PUT something ON (ie wear it).
messages are dynamically formatted on the screen, with metacharacters being used to reduce storage requirements.
references to ambiguous objects are resolved by asking the player which specific object is meant.
it has doors, some of which are operated by other devices, such as buttons or knobs. If doors are closed then attempts to move in that direction get an intelligent reply.
it has readable objects. EXAMINE and READ have the same effect for such objects.
it has containers and supporters. If you put the plastic container in the box, the box on the chair and then the chair on the table, EXAMINE TABLE will show, with indenting, just what is in or on what.
as well as carrying objects, the player can wear some of them. Carrying the space-suit is not at all the same as wearing it!
it has a number of time-dependent events, triggered by the player. Thus pressing various buttons or turning various knobs on or off can have both an immediate and a delayed response.
it has recursive rooms (the Warren of Tunnels and Somewhere in Space) whose descriptions change with time or due to player actions.
The player can move about in space using a rocket propelled back pack (which is voice actuated). The actual direction of motion is determined by the direction in which the player is facing at the time.
the player can eat (indeed has to eat) various things.
it has a couple of simple actors who respond to player inputs that begin with their name (eg ROBOT HELP ME).

A Hint to Explorers

Try examining things - several objects are containers, supporters or readable. EXAMINE will tell you more than LOOK in these cases. Note that there are 12 direction words (8 compass points, IN, OUT, UP and DOWN). SIT, STAND and JUMP can also be used to move about.

Vocabulary

The dictionary contains the following 167 words. Verbs are marked (V). Synonyms are marked (=synonym).

 a                  e (=east)          north              shutters
 access             east               northeast          shuttle
 air                eat (V)            northwest          sign
 airlock            engine             notice             simple
 all                examine (V)        nw (=northwest)    sit (V)
 an                 exit               observation        slot
 and                eye-door           of                 small
 at                 fire (V)           off                south
 back               flexible           on                 southeast
 basingstoke        get (V)            open (V)           southwest
 battered           go                 out                space
 blister            green              outer              space-suit
 blue               hangar             outside            spare
 body               hatch              pack               stand (V)
 bottle             help (V)           panel              steel
 box                hemispherical      pill (=capsule)    store
 brass              hibernation        pistol             strip
 bulky              hood               plastic            suit (=space-suit)
 but                hybo-mat           pocket             survey
 button             i (V) (=inventory) pod                sw (=southwest)
 capsule            in                 press (V) (=push)  swallow (V) (=eat)
 card               inner              push (V)           table
 cassette           inventory (V)      put (V)            take (V)
 central            it                 q                  tape
 chair              jump (V)           quit (V)           the
 circle             just               read (V)           them
 clear              knob               recorder           then
 close (V)          l (V) (=look)      red                throw (V)
 clumsy-looking     label              remote             transporter
 cockpit            large              restart (V)        tubeway
 computer           laser              restore            turn (V)
 consoles           leaflet            robot              u (=up)
 container          limbo              room               under
 control            look (V)           s (=south)         up
 craft (=shuttle)   main               save (V)           vertical
 d (=down)          mangled            se (=southeast)    viewport
 deep-space         massive            seat (=chair)      w (=west)
 device             me (=you)          send               warren
 dome               miniature          service            wear (V)
 door (=eye-door)   mission            ship (=craft)      west
 down               ne (=northeast)    shoot (=fire)      you
 drop (V)           n (=north)         shut (=close)

DECODING WHAT FOLLOWS WILL SPOIL SEVERAL SURPRISES!

To complete the game the following steps are necessary, roughly in this order. They've been encoded using a=1, e=2, i=3, o=4 and u=5:

 g2t 45t 4f th2 p4d (p5sh th2n st1nd)

 21t th2 str3p 1nd th2 r2d c1ps5l2

 g2t th2 s53t 1nd p5t 3t 4n

 g2t th2 p1ck 1nd p5t 3t 4n

 g2t th2 c1rd fr4m th2 d21d m1n's p4ck2t 1nd p5t 3t 3n th2 sl4t

 5s2 th2 tr1nsp4rt2r t4 g2t t4 B1s3ngst4k2

 g2t th2 t1p2 r2c4rd2r fr4m th2 w1rr2n. T4 g2t b1ck j5st k22p
 g43ng n4rth.

 w13t f4r th2 15t4m1t3c r2t5rn t4 th2 sh3p

 g2t th2 r4b4t t4 m4v2 th2 p4d 3nt4 th2 sh5ttl2. 1ny c4mm1nd th1t
 st1rts w3th R4B4T 1nd c4nt13n3ng th2 w4rds H2LP 4r P4D w3ll d4.

 g2t th2 c1ss2tt2 fr4m th2 M13n h1ng1r

 l21v2 th2 sh3p, 5s2 th2 b1ck p1ck t4 g2t t4 th2 m13n 13rl4ck,
 r2tr32v2 th2 sp1r2 13r b4ttl2 1nd r2t5rn t4 th2 sh3p. Th2 p1ck
 r2sp4nds t4 th2 c4mm1nd P1CK F3R2 (4r F3R2 P1CK). S3nc2 th2
 p1ck 3s 4n y45r b1ck y45 m4v2 t4w1rds wh1t2v2r y45 1r2 f1c3ng.

 g2t 3nt4 th2 sh5ttl2

 sh5t th2 h1tch 1nd pr2ss5r3s2 th2 sh5ttl2 5s3ng th2 b4ttl2

 p5t th2 c1ss2tt2 3n th2 r2c4rd2r (3t c4nt13ns s4m2 f3n1l cl52s
 1b45t wh1t t4 d4)

 5s2 th2 r2m4t2 c4ntr4l d2v3c2 t4 l4w2r th2 sh32lds

 st1rt th2 sh5ttl2

 r2m4v2 th2 s53t

 g2t b1ck 3nt4 th2 p4d

 st1rt r2-h3b2rn1t34n

 t1k2 th2 bl52 p3ll

These tasks are included in the scoring scheme. Death (there are over 20 ways to die) results in a diagnostic message which usually offers a hint.

There are a lot of things you can do wrong too! For example, try firing the pack inside the ship (both when wearing the suit and not), putting things other than the card in the slot, firing the pistol, eating the body, playing the tape in a vacuum and so on.