About the science
Chapter One covers two ideas only: that a quantum state can have several possible measurement outcomes at once, and that measurement is a physical interaction with a random result. Everything else in quantum physics is built on those, so they are worth eight levels.
How the puzzles relate to physics
Nothing here is a simulation. There is no wavefunction being computed behind the grid. The game is a set of hand-written rules chosen so that the conclusions you naturally draw are useful ones, while avoiding common misconceptions. A crate cannot be pushed by a cat with several outcomes; a camera collapses the state whether or not anyone is looking; every outcome obeys the same step, so you can never treat them as separate animals.
Things this game will never say
“Consciousness creates reality.”
Nothing in the physics requires a mind. In the game a camera collapses the state with nobody watching the screen, which is the point.
“Everything is in two states until a human looks at it.”
Superposition is not limited to two outcomes, and looking is not special. Any interaction that records the outcome is a measurement.
“A superposition is just a spinning coin; the answer is hidden, not undecided.”
Level 2 is deliberately the hidden-answer case, so you can feel that level 3 onwards is something else entirely.
“The cat is literally two cats.”
One system, one state, several possible measurement outcomes. The two pale cats are a drawing, and the game says so on every journal page.
“Particles are tiny balls that sometimes turn into waves.”
The chapter never makes that claim. It shows behaviour and names it, instead of forcing a classical picture on it.
“You can choose which outcome you get.”
Collapse in this game is random and unsteerable, which is why the entanglement chapter later can honestly say no signal is sent.
What comes after Chapter One
The chapters after this one add interference (paths that cancel as well as reinforce), quantised energy, the uncertainty principle, tunnelling, entanglement, atomic structure and decoherence. Each one adds a new mechanic to the rules you already know.