Yes. The final version will crash every 10 minutes, on the dot...
We know the game's crashing in browser. We've logged the issue and we'll try to fix it as soon as we get enough time to wade through the billion browser/hardware/OS profiles that are out there and specifically identify the problem.
As a rule of thumb, in-game crashes we can do something about, Unity plugin crashes not so much. The reason being that browsers are alternately stingy or super-free with the memory they grant their plugins, add to that how the Unity plugin changes over time AND how we can't duplicate the same problem and hopefully that puts in into perspective.
If you really want to help then, please play the most memory-hungry Unity plugin games you can find, see if that also crashes your plugin. Read up about managing plugin memory allowances, post links to optimising browser setups, that sort of thing. If we have more actual information, then we'd be able to do something, even if that something is as simple as "Hey, the Unity browser plugin is unstable and we're pushing the limits on what it can handle stably at the moment, we need to wait for Unity to upgrade the plugin."
P.S. Everyone else: If you're getting Unity Plugin crashes, please include your browser version, the plugin version and your OS when you post about it. The info will help us eventually figure out this annoying problem. I'm sorry you have to put up with Lujo's spam and my annoyance at it - I'll be sunnier and happier in future