I agree with the game worth better than the most 60$+ released nowadays but the game was free for us to try even before it got popular. devs got patreon and steam release coming soon. The least he can do for us who supported this game from 0 to where it is today is to make the update free of charge and let the steam release be a paid one. we waited a long time for this major update and then getting a slap in the face of "paid to get 2.1 update" . I'm not talking just about myself but some people can't pay 4$ because either they don't have it or they lived in another country and the price is expensive to them.
Saiko no sutoka is fun because its free and everyone can be involved in it. Just because a big youtuber give clout to this game and everyone is playing it doesn't mean they should change it to pay to get. 4$ might not seem much but some have to think of it twice.