Is Interstellar Marines in a playable state yet?

It is playable, but there's nothing much to do in it.

Playable? Yes,absolutely.Enjoyable? Nah,not yet

They recently added more foundation stuff which only means a lot for them tbh, give it another year before they start adding campaigns. Until then it's just gonna be more and more features being added without much substance for the player.

The only thing they've added in months are new maps and the ability to crouch.
It's still just a team deathmatch mode with only one gun.