SlipStream Open Beta is expected to be publicly available within 72 hours at www.slipstreamgame.comThe game can be played in the browser, any plugins needed should automatically install.For those interested in participating in the beta, please post back if you experience any issues, with a clear description and we'll do what we can to solve the issue.
Of particular interest to us is performance (framerate). Several large performance-increasing measure are scheduled to be implemented within the following weeks for the Island and the Treetop Twist. The Ring of Fire is the closest to being representative of the final frame-rate, although it is likely to receive several performance boosts with future updates.
The Browser aspect of the game is handled by Unity's Web Player. This does require you to install a plug-in; though the whole process shouldn't take more than 15 seconds before the game is ready to go.
The plug-in itself is approximately 5Mb, and is compatible with, and automatically installs in, the major browsers (Chrome, IE, FireFox, Safari). There has been limited testing on other browsers (Opera), so feel free to post about your experiences.