There is no requirement to use the Turbulenz Engine to publish a game on ga.me. You can use whatever engine you want.
(Obviously you would need to use the relevant API hooks if you wanted to use any of the ga.me web services, for example, IAP, userdata, multiplayer, play information. But this is all modular.)
This is a classic problem of trying to be helpful and it's confusing people until they understand the details.
The engine uses HTML5 and WebGL. When the required APIs aren't present it falls back onto a plugin. This is supposed to be helpful for developers because it means the games will work on pretty much all browsers include IE.
But it confuses people because some people think a plugin is required.
So what's better -
1. Not providing the fall back and telling users they need to switch browsers? Good for helping people to understand it doesn't require a plugin, but not great for developers who want everyone to be able to play their game, or
2. Providing the fallback.
Additionally, it's worth noting that the games and engine don't have to provide any plugin support. It is actually the game site application code that is doing the detection and trying to be helpful.
The Turbulenz Engine is an HTML5 / WebGL framework.
Yes you're right. Thing is, I used Safari 6 to check it out which has WebGL disabled by default. The site offered a download immediately instead of hinting that I might have to enable WebGL.
The fallback is quite a good idea, but it should've detected that I do have a modern browser which simply might be misconfigured for the game experience.
An alternate approach would be to prompt the user, telling them that using an updated browser with WebGL support (Obviously worded better for the non-technical) would not require a plugin, but give them the option to download a plugin if that is what they want to do.
The site offers to install a plugin as a fallback for browsers that don't appear to offer the required HTML5 APIs (mainly WebGL). This allows the JavaScript/WebGL games to run on a wider range of browsers (particularly IE and when required APIs are locked behind a developer switch.)
Make sure you're playing "Score Rush MP" which is the multiplayer version. You might have accidentally started the original single player version. Select the game from the "Games" dropbox in the top right of the website.