Fantastic piece of software, hugely expandable too. The easy-to-learn nature of BASIC coupled with some extremely powerful tools for manipulating graphics, sounds and, with expansions, samples and even 3D graphics.
The "Game Creator" moniker sets expectations that this package can't *quite* keep -- you still need to do actual programming, even if it is in a simple language like BASIC -- but the included accessories make things like creating sprites, maps and music a breeze. You just need to figure out what to do with them!
Later succeeded by Clickteam's Klik and Play/Games Factory/Multimedia Fusion series for Windows PC, which ditched the programming in favour of a nearly-all-in-one drag and drop solution.