The game engine is not bad. I used it a bit before I started using al's GM.
Then I left al's GM for flash...
So yea, its a good easy to use engine. Its powerful. But I would admit that it has higher system requirements than al's GM or SC.
I think that, TBH, al's GM and SC don't stand much of a chance with the younger population that have their parents buying them good macs (if they use macs) all of the time.
System requirements like requires intel mean nothing to them. Intel is about 5 years old now, and that is old enough that most parents have replaced their kids' computer.
I love GM and SC, but this is too big, too popular, and has too much money behind it for al's GM to hold up.
Mist