Quote from SabersKunk :

Don't let the alpha tag put you off though, it's fully functioning and more or less bug-free currently.

Had no problems with LFS, little things like glitches barelly matter unless it connected to physics directly and spoils the drive

to me its quite complete for something alpha, besides the few tiny glitches here and there

Quote from Exile R :

to me its quite complete for something alpha, besides the few tiny glitches here and there

Well actually I thought that s2 was done, considering that 4 years passed since s1 release so sounded realistic to me hehe..
Talked to mate, should get s1 in few days I think.