Have you written software for motion controls before? Like not gestures, but actual physical motion? I expect they quickly found out that Wiimote+[0] is not good enough for swordfighting the way they wanted it. Nothing on the consumer market is. The Razer Hydra came closest, which is why the thing they released wound up targeting it, but even then it was hard to find and too unreliable in typical use for a fun experience. (Now that the STEM is finally shipping, this may have changed.)
It's a garbage-in, garbage-out scenario that is really, really hard to solve in software. And come on, why am I explaining this to you? Why are there zero compelling or realistic Wii/U sword games?
It also doesn't sound like you've put any thought into the challenge of simulating realistic swordplay as a generic engine that supports different historically accurate fighting styles, with all the nitty physics, kinematics, and for that matter historical issues to be dealt with.
But I don't know why I'm having to defend the concept that software costs money. I think I'll just quote Neal's apology:
"Members of the team made large personal contributions of time and money to the project before, during, and after the Kickstarter phase. Some members, when all is said and done, absorbed significant financial losses. I am one of them; that has been my way of taking responsibility for this. The team had considerable incentives--emotional and financial--to see CLANG move on to the next round of funding. They showed intense dedication and dogged focus that I think most of our backers would find moving if the whole story were told. I will forever be grateful to them. In the end, however, additional fundraising efforts failed and forced the team to cut their losses and disband in search of steady work."
https://www.kickstarter.com/projects/260688528/clang/posts/9...
These were intelligent people, working with passion, on something hard. I'm glad your Kickstarter was a success, but maybe a little humility is called for.
[0] As in accelerometer+gyro, in general. It's fundamentally flawed, and you can't buy your way out of it with better parts.