Hellion is very good space sim, even if it is glitchy, it is worth playing just for it's space mechanics along with spaceship flight and destruction system. It at the start was multiplayer only game, after some time devs added singleplayer mode.
From what I remember you can self-host server for you and your friends.
For hellion only thing needed would be to get it on gog and possibly do some fixes so game doesn't crash.
I seen once that there is already somebody on github trying to make game not crash, do fixes for it.