Well, I've been playing for an hour so far, and this stamina update seems... Bad for the early game/early runs, but too good later on, let's remember that over everything the game is a porn one which means it could be pretty bad for newer people...
I really like the slight changes on dialogue and some pictures so far, but the stamina has made the progress extremely grindy and slow for the first couple of runs...
I like that some enemies take advantage of MC having no more stamina...
I want to point out that so far I haven't really been playing too much - indepth wise, but I'd say we need to gain more points for this stamina thing to work if you can pass the 14 days to get points, TL;DR:needs much, much more points, because upgrading your stats just feels too grindy...
A way to balance it would be that up until 15 attack, points required are like 20% reduced, but afterwards they're at the current numbers, that could possibly help a bit with the early run grinds...
I like the way the game's been advancing so far and I hope the dev reads some of F95 reviews and overall comments about his game, also, I haven't been using debug mode or any type of exploit ingame so this comes from a user who's playing with the standard default difficulty of the game (how it's supposed to be played since the dev wanted some feedback on the stamina)...
Edit: After advancing a bit after Deep forest, one of the main first issues one reaches is the huge difference between the old plain "Attack" without stamina usage and current stamina, I think stamina could work better and could improve the game overall, but comes with the issue that if it you're on phone and game crashes, you'll be pissed off...