Thank you for the great feedback! Some of those are the things I couldn't implement in the schedule, but I didn't think about the problem of not being able to open the catalogue in the options menu.
I chose HH because it's used as a correction prosign, but it's a good idea to use easier one (even I used K rather than HH.)
I think the game is still very flat right now. I'm planning to add more content, such as types of command, goals, etc.
Thank you for playing!