Alphas by the definition of the word are as contentless as it comes. It is right now working examples of our core gameplay loops, the next patch will have working examples of our sex and intimacy mechanics. Following that it will be the meta loop and progression systems. If you're looking for the game to have a large amount of content I would hold off purchasing until we get to the beta stage, which is all mechanics and systems in place, and a focus on content expansion begins.
Having said that you'll have access to all content patches and updates this game will receive forever. So it's not a big deal breaker to play a little earlier and help influence our content directions.