Probably Cosmic Rift: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Cosmic_Rift" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Cosmic_Rift</a> (shut down). Another 2D space MMO was SubSpace, but it was released in the mid-90s.