space-themed video game, Stellaris, cross-platform multiplayer, diverse alien races, galactic empire building, strategic gameplay, real-time with pause, diplomacy, warfare, exploration, procedurally generated galaxy, star systems, nebulae, black holes, wormholes, sci-fi, grand strategy, 4X game (explore, expand, exploit, exterminate), PC and console compatibility, seamless online experience, interstellar alliances, crossplay enabled, futuristic technology tree, alien species customization, dynamic storytelling, complex economy, multiplayer session, ambient cosmic soundtrack, detailed star maps, advanced AI opponents, multiplayer lobby, cross-platform play, science fiction universe, high-resolution textures, soft space lighting, vast universe exploration, multiplayer strategy game.