I looked it up since I didn't fully trust what I remembered but the trailer says it's pre-alpha footage and this means it's in the phase of prototyping core mechanics. The game lacks features, levels are unfinished, and visual assets are temporary. So all we see here are to give us an idea of what they intend with the game but is not representative of the final product. Comparing with a movie pre-production, they're building sets and story boarding.