Hi ^^, thanks for the comment and for playing my game, I'm happy you're enjoying it so far :3
Yes, some commands are disabled when the game begins because the letter part is some sort of little tutorial (a practical one after the initial wall of text ahah), in which the player is remembered that 'f' must be inserted before inserting any other action verbs.
In fact, as you noticed, after that the game opens up entirely.
I also wanted the player to think about the commands to insert, I didn't want the game to tell them directly, because other parts of it will require this type of thinking.
This part can be seen as the very first enigma of the game, too.
But maybe I should state that it is the tutorial part, cause actually you're not the first one to get a little stuck there, one friend of mine got stuck there too ahah ^^".
I recognised it would be a bit difficult at first to know how to proceed, so I left a hint, but it seems it is not enough ahah.
However the game is not too long, so wasting more time than needed in this section is not a big deal for the longevity of it >:3 ahahah
Anyway, if you have any other problems or comments about the game, or parts of it, do not hesitate to write :3
I'll be glad to respond and help you as best as I can ^^