It's more of a demo than a fully fleshed out game, which was developed using the Babylon.JS open source framework. The free-to-play title is a serviceable time killer when boredom hits, though more importantly, it gives a glimpse of what kind of 3D gaming is possible in your web browser, especially on touch-based systems.
"Unfurl the sails and with a swipe of your finger on the virtual wheel, steer the ship through the deep blue Caribbean. Race your ship through an obstacle course and compete with pirates around the world to obtain the highest score," Microsoft explains in a blog post. "Each time the game is launched, a variation of the original scene is delivered – with changes in the weather, time of day and location – giving you a new experience each race. Now, pin the game to your Start screen, and have it handy for those few minutes you have to spare. With split-screen browsing, you can group Skype your friends and race your ship, simultaneously."
While IE partnered with Ubisoft on this project, we found the game to run fine on Chrome and Firefox browsers, as well. If you want to give it a try, head over to Assassins Creed Pirates on the web and click "Play Demo."