Free browser solitaire games with no downloads or sign-ups
A hard sci-fi idle game evolving from the Big Bang to an interstellar civilization
Stage
Not given
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Founded
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Based in
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Pricing model
Free
Freemium
Pricing
Not given
Free with no ads; optional Supporter: $2.99/mo, $19.99/yr, or $29.99 lifetime; time crystal packs: $1.99 (Skip a night), $4.99 (Skip a wall), $9.99 (Skip a week)
Key features
Unlimited undo and hints
Instant play with no sign-up
Works on phone, tablet and desktop
Game progress saved locally in browser
15 solitaire variants
13.8 billion year cosmic timeline from Big Bang to interstellar civilization
118 sourced research cards with scientific citations
12 game eras spanning Cosmos, Life and Civilization
16 different endings
12 civilization channels inspired by science fiction and real concepts
Playable on phone, desktop and iPad with cloud save sync
Installable on phone home screen for offline play
No ads and completely free to play
1,400+ nodes each grounded in real science with sources
Physics-accurate simulation where 1 light-year equals 1 real hour
What makes it different
No required account or payments
All 58 games free and complete
Offline-compatible static web technology
Identical game mechanics across solitaire variants
Every scientific claim cites real sources with year, researcher and publication
Hard sci-fi design where physics and signal times follow real scientific laws
Completely free with no ads, payment optional and never pay-to-win
Invented game lore clearly separated and labeled apart from real science basis
Curated collection of 24+ open-source astronomy, physics and biology projects
Solitaire Online
Cosmos Era