From experience of hosting an arcade, I know that you should have plenty of web hosting space along with a lot of bandwidth. People will go around a lot of pages in your arcade looking for good games to play and each time a page is loaded, bandwidth is used. If you run out of bandwidth at the middle of the month, you won’t have a host for half of the month and that can take away activity and visitors and have a big drop in income and dedicated visitors to your site and that’s something you don’t want.
If you want to have an arcade with lets say 500 games then you should set aside at least 1.5 gigabytes of space. You are most likely to use that much or even more than that of the space amount depending on how big the files are. There are also two types of files. The SWF file which is the flash file that contains the games and the images that represent the games. Make sure you have enough space and bandwidth to host your arcade, otherwise you could be sorry.