I think people have got things a bit backwards when it comes why Amiga didn't get the same games the PC did. Sure an A1200 with an 020 and AGA and fast ram was underpowered by then, but most games were written for an A500 spec anyway: there were very few AGA only games. Why did this happen? Because for every owner who bought an AGA machine probably 10x as many stuck with their OCS/ECS-which usually was an A500. Hell, they wouldn't even buy a hard drive, so most games weren't even hard drive installable! Even a hard drive would have improved the quality and complexity of games, but no, people kept their floppy only A500's.
AGA was never properly utilized till the end of its life beacsue the perceived install base was too small for the software houses to put the time and effort to write games to get the most out of it. If they had, the next logical step would have been to write for A1200 AGA+hard drive +4 Meg RAM, then an A1200 '030 with 8 Meg ram +Cd ROM: the software would have driven the sale of hardware until AAA arrived.
If more people did buy an A1200, the software houses might have been convinced not to write their software to run on 512k A500. In reality the infamous stinginess of the average Amiga user who thought an A500 with 512 meg ram should run the latest release software for 12 years was to blame for AGA's market failure as Commodore's management was.
Going by some of the posts I've been reading on various forums it seems even today people seem to think new software should run on a A500!
