Evaluating != Purchasing?

#1 Evaluation is the norm with TGE (script wise at least), however with T2D its a little harder since the way T2D is setup means that if you had the documents showing api calls you could effectivly use T2D without purchasing it. The scripting side of T2D is so well done that it is very rare you'd need to modify the engine code to make most 2d games, although there are cases where this dosen't apply. So unlike TGE where you can use the demo and script to your hearts content then hit a barrier and decide to get a license, with T2D you could potentially script to your hearts content and finish your game.

So really I can't see a way GarageGames could provide a more functional demo for people to play around with. Any limited functionality demo wouldn't be able to show the best of T2D, since you'd need to be able to do the basics in order to demonstrate the more advanced capabilities, which again would be like giving it away for free. The best they can do is show demos of what can be done with T2D which have been released so far and there are more to come such as the Pool demo :)

The documentation is still a work in progress. With the main code still in early adopter it doesn't make sense to finalise documentation until the core is done. But again, if you had access to the reference documents you could avoid paying for T2D and still using it.

Its a shame that there isn't a demo people can get down and dirty with, but it seems in the case of T2D GarageGames would lose many more sales than they would gain by releasing a working or even limited version. Unless the limitations were quite severe, in which case the usefulness of the demo would be questionable.

This might all change in the future, I've no idea whats going on behind the scenes, but afaik for now there isn't a "working" demo like there is with tge.