Fixed-timestep loop
Deterministic updates; a huge frame is clamped, never a spiral.
Input
Keyboard state with isDown / wasPressed.
Scenes
A tiny state machine: menu → play → game over.
Save & maths
save/load plus clamp, lerp, dist, aabb, rand.
Extracted from neon-engine and Aethelgard-Engine. Pairs with web-kit for storage.