The game was offered for free at the beginning to make it known as much as possible. After that, it is not possible to proceed like that forever, backgrounds, sprites, animations, music, development, support, communication. All this has a cost.
Yes and no. They could do what Runey (hotel harem) does. Basically offer for free but ask for donations. If the creator of this game doesn't get enough he can always say, due to fund shortages I am unable to continue this project. Or even offer patreon the game 30 or 60 days sooner. And extra art work. As an incentive to join patreon.