From the little that I know about game development, the developer either makes it on their own, and doesn't release it until the game is finished, or releases it in parts so as to make sure people actually like the game. The fact that they've started the development process, and have a relatively bug free and quality looking game tells me that they most likely already have a story created, and are now just implementing it. Also if you've noticed, all the locations generally act the same way, with a certain number of hidden goodies, and a background. That looks and sounds pretty copy paste to me, which is good, because it means more to to work on the animations and story the creator(s) want to tell.
I get what you're saying, but the way they're releasing the updates in parts with little bits of each character is almost what your saying with spin-offs and other games in the same universe, but then they'd need to re-create either a new setting/environment, either from scratch, or copy-pasted from the current game, and at that point, why bother if it's copy pasted, might as well just build on what you have.
I like to think of game development as building a tower with blocks or Lego. If you build the tower too narrow, it'll never be supported and will simply fall over(rushing to finish). This also creates the base of your Lego build(video game), and allows you to start building upwards safely. If you've built with Lego, you rarely build vertically right away, rather you build upwards in a layered fashion, or after building a strong foundation. This allows the bricks to connect in a sturdy manner(debugging) for when you add the next layer(more content). I also understand them working on 1 character at a time, as it allows the story to be more meaningful, less rushed, and makes debugging the code easier.
I also can't wait for the project to be finished, but if the developer is having financial issues due to piracy or some other inconvenience, how will they pay for their home? Family? Or even electricity which is needed to create said video game? Their options are to either monetize the game, get enough support through donations sites, or to work irl on top of developing the game, which is the worst case scenario, as they'll have little to no time to work on said game depending on the demands of their job and how much they're paid.
To RNGeusEX,
We appreciate all the work you and your team are putting into the game. I personally will stick with you until this game is hopefully completed, and hope you're able to recover from your financial situation.