When I was a kid games used to fit on a single floppy! And not one of those fancy, high density kind either! They'd fit on a single, 5 1/4 disk that held 360K! Back in the day we used to play text adventure games like 'Colossal Caves' or arcade games like 'Hard Hat Mac'. Most games only had 4 colors back then and were played on monochrome screens, if you had a color monitor with 16 colors you were considered lucky!
Digitised speech is a luxury that I feel should be optional. If a retro game does
take up lots of space then it better have lots of rooms to explore, characters to talk to, and items to collect. It can be quite frustrating downloading a game that's hundreds of megabytes only to be able to beat it in less than a day. (If you're on dial up the download may actually take longer than it does to win!)
In the future the technology will probably only get better and games will get bigger. Then we will be the ones complaining to our children how games used to fit on a single DVD and you only needed a dual core 4gigahertz processor with 8 gigabyte of ram and 2 gigabyte 3D video card to run them.