Thanks a lot—these are really useful observations.
Regarding the very first hint: do you mean the absolute beginning, where there’s just a small sphere on the screen? Are you suggesting some kind of prompt to indicate that the player should click on it?
As for the purchasing process and the small button—are you referring to the minion card shop? That’s a genuinely good idea.
Regarding upgrades: I’m not sure yet how to implement your suggestion, as there are quite a few different upgrades on the skill tree, each with a unique effect. The descriptions explain exactly what they unlock or improve, and there are actually very few upgrades that simply provide a flat damage bonus. Still, I’ll give it some thought!
Thanks, bro!