Development Diary - 3D Lunar Crabs

May 2001
Well, its going to be a hard task, but after much deliberation, I decided to go for it. I wanted to do a conversion of a Spectrum game, but which one?

I tried first to do Arcadia from Imagine. I managed to get the first level up and running fine, but soon lost interest due to the lack of 'invinsibility' poke to allow me to see all the levels!

Next I looked closely at Thrusta and Android One. It seems as though most of the 'famous' Spectum games have been re-written, and so choosing a game that had not been touched, and yet known, would be difficult. (I would still like to see an Arcadia remake).

I have now settled on 3D Luna Crabs. Originally written by Mervyn Estcourt and released by Micromega. A nice little game, if a bit repetative. But at least something that had not been done before (to my knowledge!), and nice looking.

Here's the task....

Get this converted to Windows!

The game is straight forward. Scroll left/right and shoot the crabs whilst avoiding their green (spit?) missiles.

June 2nd 2001
The full sized background image has been generated. I used a fantastic free fractal landscape generator to render a large (3000 x 400 pixels) backdrop. The program is called Terragen.
I took a while to get the purple hills and yellow ground, but here the result looked good.

With a bit of work it is now scrolling about happily in a 640 x 480 window. The real game uses 360 degree scrolling, but the remake will not. At the moment the view port is 640 x 480 and the actual play field size is something like 3000 x 400. (leaving a small space at the bottom for scores etc)

June 5th 2001
Had a problem with the huge size of the playfield. The big background image seemed to be causing no end of problems. I decided to go for the block approach and so re- generated the background in sizable mountains. I then cut them out and pasted them onto the screen. This uses about 80% less memory, and so far has fixed the earlier problems.

With the new background scrolling about nicely, the next stage was to get a cannon. Before I really looked closely at the original I knocked up version 1 of the cannon.
Then I took a closer look.. mmmm! So I re-draw the cannon - and this is version 2.
Happy with this, I set about inserting it into the scrolly background.
Hurrah! The cannon is in and moving about. This is how its looking at the moment. No crabs, no ship, no firing, just the cannon and the background.

June 17th 2001
Added some nice twinkling stars to the sky. It was looking a bit empty up there!
The cannon now fires blue laser bolts off into the distance. At some stage I will add a recoil effect and barrel flash !

Crabs!
That's what It needs.... drew this as a first attempt. It actually doesn't look bad when I pasted onto a background to see what it would like like in the game.

Added a few animation frames to wave the pincers about and run across the sand.

June 19th 2001
I added the first crab to the game. It looks really nice walking about the landscape. The whole thing looks brilliant - and certainly recognisable. I dumped some more crabs (of the same type/movement pattern) in and watched as they scuttled about waving their pincers at me!
Damm things - must shoot them soon!
More crabs!
I added 4 more crab types. Different movement patterns, using the same animation. They look cool now. Load of crabs - just like the original.

Played the original for a bit (with infinite lives) to see what happened in the later stages of the game. It appears that every 150 points (15 crabs) you are awarded a 100 point bonus, and every thing starts again, unless anyone can hack into it to see if anything else happens, this is the way mine will play.
I made an attempt at the space ship today - it looked bloody awful. I deleted it, and will try again later.

June 22nd 2001
I located a nice explosion anim and with a little modification, its now on the game.
Added collision detection for type 1 crab. It now explodes nicely, very satisfying to actually blow these things up after days of watching them walk about.
Went on to do the collision for all crab types. (may add more crab types for the later levels).

June 26th 2001
Crab Spit!
Drew some green blobs that animate as though coming towards you. Dropped them into the game and added the firing mechanism.
The game is now in a kind of working state. You can kill all the crabs (getting a score of 170), although you cannot be killed by the crab spit!
The real game gets to a score of 150 before the first bonus so I will have to make a few changes.

More playing of the original to check out any other bonuses - none found yet !!
Still need a space ship! I will have to have another go at it soon.
Added a laser sound for the cannon.
Added an explosion sound.
Added a background space/atmosphere sound thing !!!

Its starting to come together now, and the whole thing looks good.

June 29th 2001
Added a flashing BONUS sign, but its not that great, and it drags about when you move, so I removed the cannon whilst it displays.
Added collision detection for the crab spit and cannon. The cannon can now be destroyed, making the game a whole lot more playable.
I drew the cannon disintegration and pasted the explosion sprite over it during the collision. It looks OK. The first level (up to 150 points) is now fully playable, although there is still no space ship !
I need to tweak some of the crab movements and maybe let the crab spit drift a bit (like the original) instead of going in a straight line.

Noone has yet answered my plee (see below) and I will be doing an intro screen soon, so I guess i'll be using the text from the cassette cover shown on WOS. Oh well !

July 7th
The first level is now complete and I also added a title screen. The game is very close to the original in the way it plays.

Finally had another go at the space ship, this time with better results. I decided to keep this one, and so its now in the game and looking good.
Level one is now complete, and level 2 plays up until the bonus at 400 points.
I am still playing the original to see if anything special happens later on, but as yet (4700 points) nothing has!

July 11th
Whilst testing level 2 - I found a weird bug. The cannon refused to fire after loosing a life, but only if you fired just before it was destroyed. I haven't traced the bug, but put in a fix to stop it happening!
Due to the (seemingly) never ending round of 150 points/bonus/next level of the original, I have been forced to change the way the new game works.
Got level 2,3 and part of 4 done.
After level 4, the game begins its 'progressive' phase. As each crab is destroyed, another one is created somewhere else on the landscape.
This means no more levels/bonuses, but makes the game better to play.

Things to do:
1- Finish level 4
2- Add a game over sequence
3- Some tidying up
4- Add some nice graphic touches
5- Start testing !

July 17th
Finally got some coding done and managed to finish the last (progressive) level.
Added the remaining sound effects and did some tidying up.
I began play testing it and managed to get to level 2. I increased the number of lives from 3 to 5, played again and got to level 4 with a score of 1750. I think i'll leave it at that and see how it goes.
Had another go on the original and for the first time (shame!) noticed that the crabs actually do spit at you. Their mouths open and shlop! Here's a grab to confirm. It's a bit late to add this to the game now :-(
If I find no serious bugs, the game should be ready to release within a week. Hurrah!

July 20th - Version 1 complete
Today I added the little monitor to the intro page - just as a fancy way of informing the player what's going on and how to play the game.
I don't know if this should be a beta or not - but sod it. Version 1 is ready to be let loose on the world. I have play tested it enough, but you can never be sure that all the bugs are out.
Hope you like it