Hi! Thank you for playing the game. 😉
As you pointed out, I’ve been thinking a lot about how to handle skill stat increases. I'm currently working on a complete overhaul of the system.
In the upcoming version, skills that add flat stats will be gained through room choices, while skills that increase stats by percentage will be available through leveling up.
I'm still actively testing and balancing the game's numbers, so I hope you'll continue to follow its progress!