Well the selection is a complicated and subjective process
First we want to know something about the developer (including their previous work) and about the project itself. Generally, because of the state the engine is in, the developers have to be capable of implementing some functionality that is commonly found in other engines by themselves, if they want to get their hands on alpha stuff. This is important because using the engine will be more challenging than using other well known engines.
Also, because the cooperation will be more tight at this stage of development, we want both the developer and the project to be fairly compatible with us, whatever it means
Our recent decision to work on our game first also changes the situation a bit, but everything will be considered.
Feel free to write to contact so we can discuss it.
Demo should be released next year, general pricing probably not.