There is no mechanic to experience the game prior to playing it. We are still in a very early testing phase, and right now we need to attract people who are willing to contribute to the game's development by pre-ordering a copy of the game, and then testing the features and balance on which development is focusing. While there may be a time in the future when there is some sort of demo (I don't know if there will be or not, to be clear), for now, the game isn't in a finished state, so allowing people to "try" the game doesn't make a lot of sense.
The Developers are currently working extremely hard to get the game to a point where it can go into Early Access, which is also why you likely have not received a reply. However, if you want to test during this phase, you will need to purchase a copy of the game when the Developers decide that you are someone who will contribute to the testing.