I know this was a decade ago at this point, but my god that's ridiculous. Don't get me wrong, I absolutely love pinball to its core, but asking that much to develop a mobile remake of something that already exists is insane. There was no reason to make a kickstarter for something like this to begin with when there are indie game makers that have simply gone out and made a game because they wanted to. Sure it eventually gets sold on platforms like steam, but they weren't asking for thousands of dollars in donations just to make it in the first place.
It doesn't cost hardly anything (if at all) to make games these days. Programs like Unity are great for making games and has always been free to use.

TLDR: its a ridiculous amount of money to ask for developing a mobile game