They know what the bugs are at this point because they are rather apparent. Enough of the game hasn't been completed for it to be tested by other members because they know they're not going to get positive comments at this stage. If anything, it will make them indifferent about making this game. Bottom line, just wait. I do think legend_master and jkartik have day jobs so you can't expect this to take priority.
It is rather absurd to have a community testing release with the intention of getting only positive comments. They should relish the fact of getting any feedback at all. After all, negative feedback is better than no feedback. This info can be used to better the game.
You do know what its like to build someone's hopes up for long time only to disappoint them....right?
Anyone who has worked with software development should have enough experience to know that not all bugs apparent. In fact, the most serious ones only show up after significant testing.