Well you did say "this guys", meaning these guys. They could very well make a game, and gathering from the Demo, they seem quite interested in a JP game.
They don't have to force their hand to make a game though, as that's up to them.
Besides, there are people out there making games that use the Unity engine anyway.
yes, but none look as impressive as ADAM series. The makers of the engine should show what their engine is capable of doing when you use it "adequately", in an actual game.
Everyone can make tech demos, but to actually having an impressive looking game is a very different thing.