As in, you clip right through and are running in midair. I mean, you can't even DO anything. This doesn't help my opinion of the game. It's important that you saw what you saw. That is what alpha in early stages is.
Alpha means incomplete.
And early alpha emans very incomplete. That's the whole point. People are flaming a game that is very, very early in development. But you won't have to wait long if you stay in the testing. New things will be added very soon and you will be able to do all kinds of stuff.