First instinct: copy Earth gravity and dial it down. Felt wrong almost immediately. The moon isn’t lighter Earth — it’s a different flight regime. And a fun regime isn’t the same as a textbook one.
Real lunar gravity is about 1.62 m/s². We started near there, then ignored the textbook whenever my hands disagreed. Players need hang time to read terrain and hazards, but not so much float that thrusters feel decorative. The Physics Tuning screen existed so I could chase that line without redeploying constants by guesswork.
Mass is the twist
Survivor cargo changes the lander’s mass mid-mission. Light outbound descent, heavy return climb — different thruster budgets. That’s why battery management became a core skill instead of a HUD decoration. Hangar upgrades (thrust, suspension, hull, battery, seats) are just named levers on the same feel problem.
Footpads, friction, and the landing zone between the poles went through multiple PRs. Soft landings had to feel earned. Tip-overs and hull breaches had to feel fair. Crash copy even got a personality pass — the mission fails with a line, not a generic game over.
Gravity does half the design work. Main thrust, left, right, fixed timestep — that’s enough for panic and triumph without animation trees. You’re tuning a toy until it sings. That’s how this shipped in twelve days, and why the first soft landing still feels like a rescue.