Eleven years after launch, Kerbal Space Program just hit its highest concurrent player count in a decade — and it’s on sale for the price of a fancy sandwich.

At $9.99 (75% off the usual $39.99), Squad’s indie space sim sits at #8 on Steam’s Top Sellers chart with 12,468 concurrent players as of May 2026. That’s the highest the game has peaked since its 1.0 release in April 2015, according to PC Gamer. Not bad for a physics playground about launching tiny green astronauts into the void.

The numbers tell the story: 94,336 reviews at 96% positive, a Metacritic score of 88, and a player base that still finds new reasons to come back. The recent Artemis 2 mission — NASA’s first crewed lunar flyby in decades — drove a wave of returning pilots, with the KSP subreddit filling up with players recreating the mission or admitting they “forgot parachutes” on their own Mun-orbit attempts.

What keeps KSP alive is its modding ecosystem and famously forgiving system requirements. One top review notes the game runs on a “2016 benchmark PC with over 50 mods.” Another player simply celebrates launching Kerbal legend Jebediah “at light speed and never need to make it home.”

The original’s resilience looks even sharper next to its sequel. Kerbal Space Program 2 peaked at just 370 concurrent players in April 2026, per PC Gamer — a rounding error against its predecessor. Where KSP2 stumbled, the original just keeps working.

For ten bucks you get a decade of community-built content, a physics engine that rewards creativity and punishes hubris, and a sim that runs on hardware from three presidential administrations ago. Hard to beat.

Sources