Invasion of the Body Snatchas!

Invasion of the Body Snatchas!
Developer(s)	Simon Brattel Neil Mottershead
Publisher(s)	Crystal Computing
Platform(s)	ZX Spectrum
Release	1984
Genre(s)	Arcade Shoot 'em up

Invasion of the Body Snatchas! is a ZX Spectrum video game developed and released by Crystal Computing in 1984.

"At last! A version as fast and furious and as frustratingly addictive as the arcade original. Landers, Mutants, Bombers, Pods, Swarmers and much much more combine to produce the ultimate space game!"

The Game

"This is a clone of defender and features Landers, Bombers, Mutants, Swarmers and Pods. There is an excellent radar screen, one you can really use for lining up shots, and spectacular explosion graphics. Sadly unless you own a Fuller Box, the game is totally silent. As usual with Defender games, there is not much colour, but the graphics are fast and smooth."

File:INBSSS.gif

Loading Screen

InGame

Notes

Like many Crystal games (and Design Design games to follow) Invasion seemed at first to be a programming exercise first, and a game second. The game consisted of a custom loader, was blindingly fast to play, and the only sound was courtesy of additional hardware that few ZX gamers owned.

A common feature to Crystal games was the bizarre Hi score table - consisting of many different quotes, and pseudo randomized so a different hi score table could be seen each time the game was loaded. Moreover, entering certain words or phrases would replace the entered phrase with another, usually either an in-joke, or continuation of the comment entered. As an example CRASH magazine criticized the speed of gameplay, so entering in "Invasion of the bodysnatchas" into a later Crystal game - Dark Star - changed the text to a phrase "Too fast for you Crash?"

Authors Notes (Simon Brattel)

There were a couple of things about Body Snatchers (I always hated the spelling 'Snatchas', which Chris Clark insisted upon in order to avoid potential copyright claims) that made it unusual. Firstly it was frame-locked, not an easy thing to accomplish with the hardware available, and secondly all the objects existed independently of the display limitations, so an alien that was off-screen could shoot at you, and you could shoot at it. This was something that was generally true of Design Design games. Note that Body Snatchers was a Design-Design game that was marketed by Crystal Computing.

In order to achieve frame-rate there were some fairly aggressive programming strategies. The objects were drawn using code-fragments rather than having character drawing routines and graphical data, there was some hideous code to undraw objects that used the stack pointer to build a definition of what was displayed on-screen, since there was nowhere near enough time to just clear the whole frame-buffer.

To minimize colour flickering most objects were drawn on 8x8 pixel boundaries and moved in multiples of 8 pixels, this being the minimum size of cell that could be assigned different colours with that display technology, and so objects moved very quickly indeed at 50*8 pixels per second...

There is a cheat code (long forgotten) that puts the game into a mode where the players ship repeatedly explodes, and during some television coverage of a computer trade-fair they used our stand as the backdrop for the report, probably the first time a Design Design game appeared on national television (quite possibly the last time as well, now I come to think of it) and this was what was running on the computer that the reporter was sitting in front of. At the end of the report he turned to the computer and pretended to play the game for a few seconds, which looked pretty silly with the ship doing nothing but exploding... Various members of Crystal Computing were visible in the background during this coverage, vying to be seen on national television; all except the programmers, of course, who were off boozing in the bar. That being the only thing worth doing at trade-fairs...

The game was credited to Neil and I, but in practice Neil had very little to do with the game and provided support on the development tool side of things; I suspect Neil would have contributed far more if the game hadn't been so boring, from what I remember of the whole process he really wasn't interested in writing arcade clones. I don't blame him, I pretty well lost interest after I'd proved to my own satisfaction that it could be done at frame-rate, which shows in the game itself - there's very little to recommend it. (Many years later I wrote a follow-up for the PC more or less as an apology for making such a pigs-ear of Body Snatchers).

There are several jokes in the high-scores, some of which have been detailed elsewhere and some of which are sufficiently obscure that they are mercifully lost to time. One that I remember fondly and which I believe has escaped documentation until now is the way the lengths of the lines of text in the high-score table were chosen so that the outline of the right-hand side forms a profile view of Graham's head (Graham Stafford was a founder member of Crystal Computing). He, I think it is fair to say, had a prominent nose, to which the term beak-like could easily be applied. As well as caricaturing the outline I was particularly proud of working the word "eye" into the high-score table entries (song lyrics) about where his eye should be... I don't think I ever pointed this joke out to him, and but for the fact I'm twiddling my thumbs writing this while a huge file downloads it would certainly have been forgotten. Ho hum, as Martin Horsley used to say.

What else? Um... The 'men' that the aliens are abducting, and which you have to rescue, are clearly depicted wearing skirts. There is a reason for this - they're women. This was a joke, something along the lines of me not wanting to write a game were you fly round picking up men. Laugh? We nearly did... There was a follow-on joke about there being bonus extra people because of what the women you saved got up to between the sheets, but it's best forgotten. I was a callow and inexperienced youth, such was my sense of humour back then.

The high-score table detected some strings and changed them to others. This is a complete list of the strings detected, what they were changed into and (as far as I can remember) why.

First there was a list of various friends, etc.

"andym" is changed to "A.Machin"

Andrew Machin was a friend, and also author of the LERM tape copier. Met him through my brother, who was a teacher at the same school as Andrew. I wandered in there one day and was stuffed in front of a class and had to give an impromptu lecture in games design... Petty much my idea of hell ;)

"chewrubba" is changed to "The Thing"

I was occasionally called chewrubba. Reference to a hairy character from Star Wars and the Spectrum keyboard, as if anyone couldn't work that out.

"motty" is changed to "N.Pottingshed"

Reference to Neil Mottershead. I doubt he ever bothered to play it to find this...

"krdt" is changed to "K.R.D.Terry"

Keith Terry is one of my oldest friends, who probably hated the game ;)

"alanw" is changed to "A.Walker"

One of my earliest friends.

"rozzer" is changed to "R.Walker"

Rosalind Walker... Sigh. Alan's beautiful sister, the first girl I kissed seriously. God, I wanted her... Hell, I still want her ;)

"johnl" is changed to "J.Lawrence"

And another very old friend, who I have completely lost touch with...

"meb" is changed to "Hello Maria !"

MEB were the initials of Maria, Martin Horsley's girlfriend. Neil and I lusted after her as well... (Martin, Neil and I had previously written Halls of the Things).

"maria" is changed to "Programmers in general eh ?"

Maria again - I once asked her at a party if she was interested in Martin or just programmers in general. She said programmers in general, but she was only trying to fend off my drunken advances. Hang on... Sounds like she was encouraging them... Blast! Where's my bloody time-machine? [later-earlier-later again] Nope, fending off it was...

"mash" is changed to "Smart arse"

Mash was Martin Horsley's nom-de-high-score table. I suspect this entry has something to do with his relationship with Maria, the lucky bastard. Might also be a reference to "Rommel's Revenge", which he was developing at the time. I can't be sure now...

"dave" is changed to "The cardboard box !"

This is (a) a reference to comic sketches in one of Jasper Carrot's series. Googling will tell you more. But it's really intended as (b) a way to take the piss out of a friend of Neil's who was called Dave, surprisingly enough. Any other Daves are collateral damage and I apologise profusely...

"jdg" is changed to "Hi Jim !"

JDG were the initials of James Garside, another old friend. Jim and I had been sharing a flat while we were at university. It was where most of Halls was written.

"c.c.c" is changed to "Chrisipoos"

C.C.C. -> Christopher Charles Clark, I think. Chris was one of the founders of Crystal Computing. I'm not sure if we were getting on well at this point, a bunch of us were about to stage a revolution and start trading directly as Design Design.

Then there are a few HHGTTG-ish references.

"whatisthe" is changed to "42 of course !"

"marvin" is changed to "Life don't ...."

"zaphod" is changed to "It's easier with three arms I suppose"

Then there are a few general references.

"kickaha" is changed to "P.J.Finnegan"

Kickaha is the name used by the character "P.J.Finnegan" in Philip Jose Farmer's World of Tiers series of fantasy books. But it's a reference to a reference, because "P.J.Finnegan" has the initials "PJF", the same as "Philip Jose Farmer", so Kickaha is a reference to Farmer as he'd like to be, as indeed would I. That series were and still are some of my favourite books... Kickaha was also the default name we used for the initial high-score in Halls of the Things, and I suspect there are other references to The World of Tiers series in the other games.

(Kickaha is a native american name for a trickster, to put it very loosely. A role I'd relish if I were only cunning enough <grin>).

"cheesecake" is changed to "Greens Original"

Neil was officially the catering manager - this is true, we had one for some arcane reason or other - glomming free food, I'd imagine, and in this role he often made chicken curries to a recipe that his mother had given him. They were excellent. Afterwards, well frankly after any possible excuse, we would have a Greens Original cheesecake. In fact, I'm tempted to go and have one now... There were other references to these scattered about.

"6502" is changed to "Crappy processor"

Need I say any more? I have designed better processors in an afternoon. So have random CAD system crashes...

"darthvader" is changed to "Boring tit !"

God knows. I can only surmise that someone I've forgotten used to enter "darth vader" in high scores...

"xyzzy" is changed to "Wrong game !"

xyzzy was a magic word in one of the first text adventure games (Colossal Cave).

"blach" is changed to "Bells ring etc ."

I suspect this is a reference to a bug in the spectrum game "The Hobbit", but I couldn't swear to it now. I'd try entering it into The Hobbit and see if bells ring, etc...

"sex" is changed to "Yes please !"

"fuck" is changed to "Like too !"

Ah, the depressed innocence of youth. If only we'd known then what we know now. But don't get me started on sex ;)

"cheese" is changed to "Cheese ?"

This is obscure. The first version of the high-score table code, which few people ever saw, didn't recognise all these text entries and change them individually, it just recognised the word "cheese" followed by a number and then it outputted different messages. This is a reference to that early phase of the code. And to our, well, frankly our obsession with cheese. Ok, ok - my obsession with cheese. Cheese and sex, sex and cheese, how could this combination be improved upon? Very easily.

"lavinia" is changed to "She's moved to 061-205-6603"

In Halls there's a reference buried in the code (for hackers to find) to "Lavernia's Massage Parlour" which gave the telephone number of the flat I was living in (sharing with JDG) at the time it was written. There was no actual lavinia, but there were a couple of sisters living upstairs that we used to dream about. One was called Sylvia and I'm sorry but I forget the name of the other. For some reason Sylvia lent me her copy of "More Joy of Sex", which was an evil thing to do to a desperate virgin; almost, but not quite as evil as having her bloody bedroom right over mine and having a bed that squeaked. Gah... Somehow their flat became known as "Lavinia's Massage Parlour"... Ah, but they were far too sophisticated for the likes of us, penniless students as we were...Sylvia's boyfriend had a BMW, for gawd's sake. What chance did we have? Sob...

On one memorable drunken evening I'd rigged up my development machine so it would record audio and play it back backwards. (This was advanced stuff for 1982, or at least it seemed like it then) and Martin, Neil, Jim and I sat in my room thinking of things to say and trying to learn how to say them backwards. Don't ask me why but Martin came up with "Sylvia has big nipples" and then spent a good half an hour learning how to say it so that when it was reversed it was perfectly intelligible. What with this and the coke-bottle fights (the flat was full of 1.5-litre plastic coke bottles) where everyone took turns to throw coke bottles at everyone else let it not be said that we didn't know how to have a good time...

Where was I? Ah. Yes. Sorry.

"speakertoanimals" is changed to "Chmee"

A reference to a character from Larry Niven's Ringworld series. Some more of my/our favourite books.

"spectrum" is changed to "Ghastly rubber thing"

We didn't much like the Spectrum, in fact I probably like it more now than I did then - twenty more years of the computing industry have significantly lowered my expectations.

"crystal" is changed to "Design Design Software"

And very soon after this was published, it did..

"hott" is changed to "Halls"

I didn't particularly like "hott" as a name for "halls", it has grown on me, I suppose.

"tony" is changed to "A blaze of trumpets & singing angels"

This is a reference to the first published review of "Halls" which was probably the most accurate and interesting review we ever received for any of our games. Tony is Tony Hawks - the reviewer, if I remember correctly. He used the phrase in the review...

Reviews

Reviews can be found in the following magazines....

"Invasion of the Body Snatchas is an essential buy for all arcade fans" Sinclair User

"All in all probably the best version for the Spectrum yet" Crash 69%

"A very enjoyable and addictive game. Highly Recommended" ZX Computing

External links

• Invasion of the Body Snatchas! at SpectrumComputing.co.uk
• Invasion of the Body Snatchas! original source code at Design Design