If you just want to play a fun game, wait until it's more complete. Game is so WIP that the whole world gen is expected to change soon (to their "V2" world gen) which might break old saves. There's very little content beyond the generated structures and terrain and some decorative blocks. Even the current "endgame" can take just a few hours to reach, and there isn't much there.

Friend and I have about 6-8 hours in it and I would say that while it is quite fun with what is in it, it's very much early access. Some things don't feel fully fleshed out, a lot of structures that do generate just have a WIP sign inside the front door, small bugs here and there. I would give it another few months if you're still on the fence unless you want to give them some dev funds. I imagine between actual updates and mods a few months from now will feel much different. I think the minimum price was $20, with a $35 and $70 option with some cosmetic bonuses.