Why is there no beginner guide or glossary of terms for this game?

I'm enjoying the game so far but there's so much missing info that I'm struggling to understand what to do until I've tried it and failed.

What do all the abilities and terms mean? There's literally no way to look it up! Not in game or in the wiki! Like I just want to know what the basic powers are and some terms like "agility"and "bearded". There's literally no way to find out! Not even this reddit seems to have (easy to find) answers!

Also, what does purchase the game mean? At no point in the game does it tell you what you get from buying it other than the rewards screen telling you you'll get more rewards. Does it do anything else? Why isn't this in the store page or in the game?