Hi. I did a little forum cleanup to move your question to its own thread, and to get it what I hope is a fairly representative title.
Unfortunately, you're basically asking for something impossible. An eighteen-minute short at 60 megabytes would have to have a data rate of about 460
kilobits per second. The data rate for HD compressed with the best codec available is in the 5-8 megabit range.
Obviously you should try compressing your short down to 460 kilobits to see what you think of the results. Who knows; you might actually find it acceptable for your purposes.
But your best bet is to get the raster size down to something more in line with that data rate. You're probably going to have to go down to something less than SD; I've never gotten acceptable results on SD material from H.264 at less than around 800 kilobits per second or so, and frankly that was extreme.
The best solution is obviously to deliver your short in some other way; sixty megabytes is simply not a reasonable file size for an eighteen-minute film. But if that's just not an option, period, then you're going to have to do some experimenting with different raster sizes and data rates until you find something you can live with.