I can't understand how nobody has commented your game yet, it's amazing ! I love this kind of games and really enjoyed it ! (I even replayed it several times)
The overall design is really well made and walking through the manual is really cool ! I would love to have a printable version of it.
The only tip I can give you for this game is to rewrite the manual with better explanations to avoid confusing the player with sometimes not well explained steps (e.g. the "Size" chapter). Converting planets name to code was a bit difficult (never got the Earth conversion working, strangely) but finding it myself gave me a more rewarding feel.
Really cool game and I'll definitely look over your other projects and the future ones !