Yes, worth buying, especially since it's so inexpensive.
The game is Early Access. It's not complete. People complain about how long it's taking to release new material, but the devs are releasing updates on a regular basis. These have not been the unfinished biomes, but rather quite a few bug fixes and some additional material for biomes already in play. (We saw one large update to the food and building system early on and some additional material for the Mountain biome.) But no, the game isn't dead, and there is stuff in the pipeline.
As far as gameplay goes, it's pretty unforgiving to people who rush into regions and situations for which they're unprepared. I personally haven't had to do a naked corpse run in a game for many years, and I love that aspect of it. Take your time, see the sights, learn from your mistakes and I think you'll have a great time.