Check out these two programs. Both are completely free and allow you to make pretty decent games.
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Al Staffieri's GameMaker v2.9.1 -
http://alstaffieri.com/macsoftware/classic/gamemaker_291_freeware.sit
I've known Al for a long time online, over 10 years. Recently I got him to release an older version of his GameMaker program for free.
You can create card based games similar to HyperCard, including a scripting language, and compile them into stand-alone programs. You can run QuickTime movies within your game to add extra realism. The game editor and compiled games are 68K programs that run on System 7 and up. The games are really small and light on resources. There's an even older version (with no scripting language) that runs on System 6.
GameMaker is still developed. The latest version runs on OS X but is not yet a Universal Binary. v4.0 is in development (a complete rewrite) which promises full Universal Binary and advanced new features.
http://www.macgamemaker.com
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Mike Richardson's SilverCreator v1.5 -
http://www.silvercreator.net/downloads/SilverCreator1.5PPC.sitx
This is my own program similar to GameMaker, but with more advanced features. It has a more advanced scripting language that includes sprites, file access,
easy sockets/Open Transport, timers, more advanced scripting, etc. The editor runs on PPC only, but you can compile games for 68K, PPC, FAT, and OS X (PPC). My program is a bit more bloated than Al's though, and requires at least Mac OS 7.6.1. v1.5 is a generally stable release with only a few known bugs.
I still develop this, and the newest v2.0 betas are Universal Binaries but drop support for Classic (http://www.silvercreator.net/plaza/). All versions are free.
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Stop being so Complicated. Take a RISC.
http://www.adoptamac.com