Don't download the game everytime i play

Can the users play my games from the web using the cache of the computer? I don’t want that they have to download all the game every time they play. Any other idea to reduce the time every time they play will be welcome.

This refers to the use of Asset Bundles I believe:

What is the Unity caching product and
how can we license it?

We offer a special extension of the
Unity Webplayer which can cache asset
bundles locally. This is licensed
under an agreement made by our
business development team. Generally
it is licensed to developers with a
large anticipated revenue and not on a
smaller scale basis.

http://unity3d.com/unity/faq

Otherwise, read this API page