- Once upon a time, the city Arcadopolis was attacked by the evil Slime people, who intended to enslave the poor citicens of the city. However, their evil plans were discovered by the Arcadopolis Special Intelligence. A special defense system, the Slime Defense Initiative, was organized. When the slimes arrived, the defense system was ready...
- Stop it! Stop it! Please, what are you trying to tell us? It's just a stupid game, no science fiction novel!
- Ahem... OK, I guess you are right. How about this, then. This is Slime Invaders, a shoot-em-up game for the Macintosh. The game is in the Space Invaders genre, with a gun at the bottom of the screen and various enemies attacking from the top. 8 different enemy types, fast enough to be enjoyable on a Classic. Black-and-white graphics.
You are allowed to make changes for personal use, e.g. replace sounds if you don't like the present ones, but you may not redistribute it in such a form. If you want something changed in the distributed version, ask me and I might put it in.
3. Using Slime Invaders
Start a new game with "New game" in the "Game" menu.
During the game, you do not have access to menus, but you can pause the game with cmd-p or abort it with cmd-period.
The game itself should be rather intuitive. Shoot everything, don't get hit. The gun is controlled with the mouse. When (not "if"!) you do get hit, your next gun appears on the right, and will not enter the game area until you click the mouse button.
A few notes on the enemies: The "slimes" are present in all levels, but the stuff they throw at you varies. Note that this game, like many arcade games, has "smart bombs" - but not used by you... To make matters worse, the horrible "death" appears if you take too long to clear a level.
If you switch from Slime Invaders to another application, the game hides its game window. This is done to give you a chance to access the disk icons, trashcan etc.
4. Compatibility
Slime Invaders should run on all Macintoshes with System 6 or later, with or without MultiFinder and hopefully under System 7. The game has been tested on a wide range of Macs. It was developed using an accelerated Mac SE (16 MHz 68000) and a Mac LC both running System 6.0.7. The development system was Think Pascal version 4 with the TransSkel library by Paul duBois.
I have made quite an effort to make this game run on all Macs, especially with various screen sizes. I have not been able to test it with multiple screens, though, so I make no promises there.
For a game like this, the speed of the graphics is very important. It is highly recommended that you set the screen to 1-bit (b/w) mode.
To achieve high speed, most games draw directly to the screen, but this often makes them brittle. Slime Invaders allows you to choose whether to do this or to use the standard routines (slower). To get faster graphics, check the "fast animation" menu item.
Another option which is included for compatibility reasons is the "allow background tasks" option. With this option checked, your background tasks (e.g. SuperClock) will run. However, the game may run less smoothly, and there is a risk that you happen to switch to another application by mistake by hitting the icon in the right end of the menu bar (System 6).
Also, when you die and get a new life, it is very nice if the game changes the mouse position, but this relies on a feature that is not guaranteed to stay, so if the program breaks just when you try to re-enter the game field, try unchecking "Reposition Mouse". (This might be necessary under A/UX, but that is just a guess of mine.)
Finally, the game uses the old "Sound Driver", which might be dropped in the future. (I hope it will stay, since it is much easier to program than the newer Sound Manager.) If your system doesn't support Sound Driver, try playing with the "Sound" option unchecked.
5. Acknowledgements
The help from especially Eva (who doesn't even really like arcade games), and all ideas and suggestions from the testers are much appriciated.
6. Final words.
I made this game because I wanted to learn how to make decent animation on the Mac, animation of several objects over a background the way that shareware authors like Duane Blehm (Zero Gravity, Cairo Shootout) and John Calhoun (Glider, Glypha etc) do. I'd say I manage pretty well. In case someone wonders why I waste my time writing silly games, my answer is that I both learn a lot about fast graphic algorithms (an important issue in my work), and I keep my programming skill alive during periods when my work is only report writing. The only real waste is polishing and writing doc files like this one...
As stated above, the game is free, but if you send me at least $10, I will send you a diskette with the latest versions of my games. (Bikaka, Hexmines, Skiing Game, Slime Invaders, Classic Daleks, MacSokoban, Backman.)
I also enjoy fan mail, suggestions and bug reports. Send them either by E-mail to ingemar@isy.liu.se, or by ordinary mail to:
