Hi! Apologies for this reallllly late reply, as I have not been active in making games as of late.
* Ideal game group for AGGG can consist of 3-4 players and 1 GM. But the game itself can run on more players given the game's focus on the conversation and not on the game mechanics loop.
* Average play time is 2 to 3 hours for each session or adventure. Noted on adding game time.
* Solo mode is currently not part of this game.
I understand the frustration, as this game is initially designed to be a hack of 2400 games (see link to 2400 game jam in description to find out more), so it is intended to have gaps in the rules. You will often see it in other games as well if they are part of a game jam, or intended to be a hack or supplement of another game.
I appreciate the interest, and I hope the answers above are sufficient. Feel free to ask more questions if needed.